Locate any enclosed spaces on the drawing. This is any space that has lines all the way around and will be a solid color. Click on the paint bucket tool in the tool bar to the right of your screen, then select a color on the color wheel at the top of the toolbar. Click the cursor in the enclosed space to fill it with color. For a different area, select another color and click in the second area. This is the easiest way to color in PaintTool SAI.
Select the magic wand tool from the toolbar. Like all of the tools, it is clearly marked with the name of the tool beside the icon. This is the second easiest way to color large areas in PaintTool SAI. Hold your left mouse button while sweeping the wand around an area of the image that will be a solid color.
Release the button. The area selected will be highlighted in blue. Select a color for this area from the color wheel. Click the color.
Continue using these methods until the majority of the picture has been colored. Use the zoom tool to magnify detailed areas. Select the paintbrush to color the smallest areas.
Select the blur tool to add highlights or blend colors. It is near the bottom of the toolbar and says "Blur."
Select the File menu, then "Save" to save the work. You also can select "Save As," then JPEG to save it as an image file that can be opened in other programs.