To start off with, create a simple shapelets say a rectangleand fill it with a basic linear gradient. Use the Color Mixer panel to set your colors, and if you need to, use the Paint Bucket tool to apply it to the shape youve already drawn.
From Adrien-Luc Sanders, former About.com Guide
To start off with, create a simple shapelets say a rectangleand fill it with a basic linear gradient. Use the Color Mixer panel to set your colors, and if you need to, use the Paint Bucket tool to apply it to the shape youve already drawn.