[Zoolok]

Here's one I can answer!
Select the color palettes (3rd icon in the color picker, e.g. from the fill inspector)
Near the top is a pop up menu: Select "Web safe colors"
Next, near the bottom is a pop-up selector with a text entry box. Type the hex value for the color in there ... eg ffffff gives white

It doesn't seem to give all combinations, but it might be a start!