yeah right. history window can view all the hsitory of your works and you can go back or undo until the beginning of your works or you can also view all your works history
http://images.bravenet.com/bravenet/images/c/bravenet/images2/tipsandtricks.png
http://images.bravenet.com/bravenet/images/c/bravenet/images2/title.gif
On the web we work in a color space called RGB ...
try this also: make one color in one area of your drawings then try to use DODGE TOOL which will make hard color to light color but in faded style. And try also to use BURN tool which will make light ...