How to Create a Rainbow in Illustrator CS3

Make a rectangle using the Rectangle tool. Use Alt+drag and Shift key one time down to the right position. Click Control+D three times. To change the colour, select the rectangles one by one and by clicking on a swatch. Choose all the rectangles and group them. Navigate to Effect>Warp>Arc. Change the Horizontal percentage to 80%. Click on Expand Appearance. Now Continue Reading