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13. DIGITAL COLOUR THEORY Nowadays in this changing era there is a shortage of time and the material to utilize for testing and experimenting with various colour media to design different colour schemes and working on various colour harmonies for a number of projects has become too expensive to be done with traditional tools and equipments. So, for the introduction of computers in the world of art. This final unit of the course will introduce you to drawing and designing and coloring has become unavoidable. Thus the last unit is going train you in the colour and texture management with the help of computers.

13.0 Objectives After going through this lesson, you will be able to: •

Understand the colour theory of computer that is based on light emission.

Use all the colour and texture management tools of Corel graphic software skillfully.

13.1 Introduction You have already studied abut the colour wheel (Lesson4), colour schemes (Lesson8), type of colours, colour families (Lesson3) and colour harmonies (Lesson7). The first colour wheel was invented by a great Scientist, Sir Issac Newton around 1666. He observed that white sunlight passes through triangular prism; it splits into a spectrum of seven major colors, viz. violet, indigo, blue, green, yellow orange and red beams, named VIBGYOR. After another 100 years, Johann Wolfgang Goethe studied psychological effect of colours i.e. the effects produced by the colors on human beings. He created a Colour Wheel showing the psychological effects of each colour. According to him, the colours from red through orange to yellow (termed plus side) produce excitement and cheerfulness, while the colours from green through blue to violet (termed minus side) are associated with weakness and unsettled feelings. Johannes Itten, a colour and art teacher at the School of Applied Arts in Weimar, Germany, developed the current form of colour theory. Itten's Colour wheel is based on red, yellow, and blue colours as the primary triad and includes twelve hues. In Lesson 4, you saw the artists’ cardboard Colour Wheel, with Red Yellow and Blue (RYB model) as Primary colours, mostly used in designs and art works. The primary colours are placed next to each other. The three secondary colours, viz. Orange, Green and Purple, are formed on mixing two primary colours. Secondary colours are usually more interesting than primary colours, but they do not evoke speed and urgency. Tertiary colours (Yellow-Green and Red-Violet) 2

are made by mixing one primary colour and one secondary colour. There can be endless combinations of tertiary colours, depending on how they are mixed. When you look into the colour model in computers, which is based on light emission, the three primary colours are Red, Green and Blue (RGB, with green replacing yellow in the RYG model). You may also note that the colours that are most harmonious or complementary are not across from each other on the RGB colour wheel. Combination of Red, Green and Blue are used to produce different colours on the Computer or in Television. The image displayed on the monitor screen is a combination of small dots known as pixel and the colour image is a combination of different colour dots derived from RGB model. Thus, when we design on a computer or television monitor, we deal with light and the colour theory changes from artists RYB colour wheel model on cardboard to RGB model. However, the RGB colour model is only used with light sources, and it does not apply to printing.

13.2 Colour Base: Ink vs. Light Artists’ cardboard Colour wheel that has been traditionally in use chooses colours from “RYB” and is based on printing inks. However, when we design on a computer (or television) monitor, we deal with light. A side-by-side comparison of these Wheels is shown in Fig. 13.1:

Fig. 13.1

To work with colours efficiently, you have to understand the foundations of the colour separation. If you see from the Colour Wheel, the base R-G-B colours comprise of three sets of complementary colours: Red < - > Cyan Green < - > Magenta Blue < - > Yellow When you adjust a colour, its complementary colour is affected as well. For example, by increasing the amount of Red colour (+) in an image, you automatically decrease Cyan (-); decreasing Red (-) increases Cyan (+). Similarly, If you reduce (-) or increase (+) Green, the amount of Magenta grows (+) or reduces (-), respectively. Similar relationship exists between Blue and Yellow. This relationship of colours must be remembered when you use channels 3

for colour adjustments. Thus, select the red channel to adjust red and cyan colours, select the Green channel for green and magenta and select the Blue channel for blue and yellow. As a designer, your job is to make others look good, whether the final piece is a logo or a packaging design or a Cloth Design. Choosing right colours is, therefore, extremely important. The four scientifically proven colour schemes, viz. Monotone, Monochromatic, Analogous, and Complementary, are described in Lesson 7. To understand how colours may be applied, we will use the Graphics Software â&#x20AC;&#x153;Corel Drawâ&#x20AC;?. We would use the software here to understand more about colour usage.

13.3 Exercise 13.3.1 Working with Fills (filling colours in objects) You will learn how to use colours and apply them to different objects by drawing some shapes on computer screen and filling them with colours. There are a number of tasks that are common to all types of fills. You can choose a default fill colour so that every object you add to a drawing has the same fill. You can also remove any fill, copy it to another object, or use it to fill an area surrounded by an open curve. i) Colour Palette Fill Click on the desired colour in the colour palette. The selected object will be filled with the chosen colour (Fig. 13.2).

Fig. 13.2

ii) Drag Fill from Palette Click and drag the desired colour over any object (does not need to be selected). The cursor will change to a solid square of the chosen colour (Fig. 13.3). Release mouse button and the object will be filled with that colour. Fig. 13.3

iii) Fill Tool Solid Fill Click on the Fill Tool in the Toolbox to open the fly-out (You can click and drag on the fly-out border to have it remain on your workspace for easy access to fill options). Choose the first icon to open the Uniform Fill window (Fig. 13.4). Choose a colour and click OK. The selected object will be filled with that choice. Fig. 13.4


iv) To Choose a Default Fill Colour •

Click a blank area on the drawing page to deselect all objects.

A drawing page is the portion of a drawing window enclosed by a rectangle with a shadow effect.

Open the Fill flyout, and click the Fill Colour dialog.

In the Uniform fill dialog box, enable any of the following check boxes: o o o o

Graphic applies the default fill Colour to shapes you draw Artistic text applies the default fill Colour to artistic text you add. Paragraph text applies the default fill Colour to paragraph text you add. Specify any fill settings.

v) To Remove a Fill •

Select an object.

Open the Fill flyout, and click the No fill button marked X. It enables you remove a fill from an object.

vi) Draw a Rectangle •

Open the Rectangle flyout, and click the Rectangle tool.

Drag in the drawing window until the rectangle is of the size you want.

vii) Draw a Square Open the Rectangle flyout, and click the Rectangle tool. Hold down Ctrl Key, and drag in the drawing window until the square is of the size you want. viii) Draw an Ellipse Open the Ellipse flyout, and click the Ellipse tool. Drag in the drawing window until the ellipse is of the shape you want. ix) Draw a Circle Open the Ellipse flyout, and click the Ellipse tool. Hold down Ctrl Key, and drag in the drawing window until the circle is of the size you want. x)

Filling These Objects with Colours You can add Colour, pattern, texture, and other fills in these objects. You can customize a fill and set it as a default, so that each object you draw has the same fill.


xi) Understanding Fill Types Fig. 13.5 contains a selection of fill types. The background square contains a bitmap fill; the circle, a graduated radial fill; the rectangle, a solid colour fill; the star a texture fill and the text a linear fountain fill. These are basic applications of each fill type. Each application is covered in a step-by-step process in this series. This simple example is to give you an idea about the powerful fill options that you will learn.

Fig. 13.5

xii) Uniform or Solid Fill Overview Uniform or solid fills are the most basic fill (Fig. 13.6). Select an object with the Pick Tool (create one if necessary). Click in the colour palette with an object selected to fill. You can also use the Uniform Fill dialog or click and drag a colour from the colour palette. xiii) Creating and Applying Solid/Uniform Fills to Objects

Fig. 13.6

Fills can be applied to any closed object. Select any object with the Pick Tool or create an object. You can select multiple objects and the fill you choose will be applied to all selected objects (Fig. 13.7). xiv) Uniform fill: A type of fill used to apply one solid colour to these objects. Fig. 13.7

• • • •

Select an object. Open the Interactive fill flyout, and click the Interactive fill tool. Choose Uniform fill from the Fill type list box on the property bar. Specify the settings you want on the property bar, and press Enter.

Note: You can also fill a selected object by clicking a Colour on the Colour palette. Colours can akso be mixed in a uniform fill by selecting a filled object, pressing Ctrl Key, and clicking another Colour on the Colour palette. xv) Fountain Fill Overview Fig. 13.8 shows the four basic types of fountain fills. The top row features a linear and a radial fountain fill. The bottom row contains conical and square fountain fills. The fills to the left are accomplished by selecting an object with the Pick Tool, clicking on the Fill Tool to open the fly-out. Click on the second icon to open the Fountain Fill window. All fountain fills are completed from this window.

Fig. 13.8

(a) Fountain Fill Window Fountain fills allow you to automatically blend two or more colours within an object. Fountain fills create a 3D 6

Fig. 13.9

appearance in graphics, you can add soft blending effects to your drawings (Fig. 13.9). Select any object with the Pick Tool. Choose the Fill Tool to open the flyout, and choose the second icon to open the Fountain Fill window.

(b) Applying fountain fills So if we see this image, we can view that a fountain fill is a smooth progression of two or more Colours that adds depth to an object. The four types of fountain fills are defined as below: • Fig. 13.10 Linear Fountain Fill

The samples in Fig. 13.10 show a linear fill from medium green to a light green. The lower sample shows a 45 degree rotation of the fill. •

Fig. 13.11 Conical Fountain Fill

Fig. 13.12 Radial Fountain Fill

A Linear fountain fill, flows in a straight line across the object.

A conical fountain fill creates the illusion of light hitting a cone.

Conical fountain fills create a cone like appearance with the conical point appearing higher than the edges. In the Fig. 13.11, the top sample is filled with default conical fill settings. The bottom sample has had the colour midpoint, the center offset and the fountain angle adjusted. •

A Radial Fountain Fills blend colour in a circular pattern. You can create instant 3D spheres with a couple of steps with radial fills. In the Fig. 3.12, the upper circle is filled with default settings. The lower circle has the center point adjusted, the fill blend moved towards the lighter colour and a pad of solid edge colour added to it.

A Square Fountain Fills apply colour blends in a square pattern. In Fig. 13.13, the top text is set with default values. The lower sample fill has adjusted center point, colour midpoint, angle and colour edge padding.

You can apply preset fountain fills, two-Colour fountain fills, and custom fountain fills to objects. Custom Fig. 13.13 Square Fountain Fill fountain fills can contain two or more Colours, which you can position anywhere in the fill's progression. After you create a custom fountain fill, you can save it as a preset.

Self-check Questions 1. How will you fill colour in an object from a colour palette? 7

2. How can you fill colour in an object from palette by dragging the mouse? 3. Write the method of drawing a square and a circle in Corel draw: 4. If you want to remove colour from an object, what will you do? 5. How many types of fountain fills are available? 6. How will you fill the object with i) Texture Fill and ii) Radial Fill? 7. How will you open pattern fill dialogue box in Corel draw? 8. Write the full form of VIBGYOR.

Activity 1. Make a composition of geometrical shapes, using rectangle, circle and triangle, you can repeat a shape if your design requires so. Then fill these shapes with different effects, you can use colour fill, fountain fill, pattern fill, texture fill etc. NOTE: Do not repeat the same filling effect in any shape, create a new for each.

13.4 Assignments 13.4.1 Class assignments i) Learn more about colour palettes and colour schemes. 13.4.2 Home assignments i) Create different shapes and work with fills using Corel Draw.

13.5 Summing Up As this lesson lets you enter into a fascinating new world of computerized drawing, painting and designing, by now you must have understood the importance of computers for an artist. This lesson has introduced the software that is called Corel Draw and which can help you to create any kind of shape and fill to fill it with any kind of colour, pattern or a texture, just with a mouse click.

13.6 Possible Answers to Self-check Questions 1. First select the object which you want to fill, then click on the desired colour in the colour palette. The selected object will be filled with the chosen colour. 8

2. First click the desired colour in the palette. Then drag this colour over the object and then the cursor will change to a solid squqre of the chosen colour and finally release the mouse button and the object will be filled with that colour. 3. Square - Open the Rectangle flyout, and click the Rectangle tool. Hold down Ctrl Key, and drag in the drawing window until the square is of the size you want. Circle - Open the Ellipse flyout, and click the Ellipse tool. Hold down Ctrl Key, and drag in the drawing window until the circle is of the size you want. 4. To remove colour from an object: a. Select an object. b. Open the Fill flyout, and click the No fill button marked X. c. It enables you remove a fill from an object. 5. Types of fountain fills are: i) ii) iii) iv)

Linear fountain fill Radial fountain fill Conical fountain fill Square fountain fill

6. a) Texture fill: Select the object, click fill tool select the texture fill dialogue box, from fill flyout, select the desired texture you want ,click ok, and the object will be filled with your chosen texture. b) Radial fill: Select the object, Click the fountain Fill dialogue box from fill fly out, select Radial from the type of fountain Fill and click OK. 7.

Pattern Fill: Click the Pattern Fill dialogue box from fill tool box fly out.


Violet, Indigo, Blue, Green, Yellow, Orange, Red

13.7 Terminal Questions 1. What is the difference between colour combinations in normal art work and that on computers? 2. What are the various colour models used in computers? 3. What colour model is used for printing from computer and why?

13.8 References and Suggested Further Reading Internet Websites: 1. Colour Wheel Pro: 9

2. Corel Draw Help Menu 3. Online Tutorials on Graphics Software

13.9 Glossary 1. By Default


2. Conical

Cone shaped

3. Linear

Straight line form

4. Blend


5. Cheerful