Scratch

Scratch uses the HSL model to change the color of a sprite/pen. We can change the Hue (change color to/by) and Lightness (change shade to/by), but Scratch is missing the third, also very important component, the Saturation.

[set pen saturation to ( )]
[change pen saturation by ( )]
[set [saturation] effect to ( )]
[change [saturation] effect by ( )]

If these four simple blocks would be implemented, Scratch would be able to display all displayable colors on the computer (without using the [set pen color to [ ]]-block). This would be very useful for drawing programs.

This is a very nice project that also explains the problem. A Scratch Team member posted a comment about the saturation blocks being "confusing". Well, I don't see anything confusing about that.

I'd love to hear from anyone with opinions on the Scratch colour model!