The KnownColor command returns true if color is the name of a color in the palette P.  It is useful for avoiding the errors thrown by the Lookup command for colors not in a palette.

$P≔\mathrm{ColorTools}:-\mathrm{GetPalette}\left(''CSS''\right)$

$P≔⟨Palette\; CSS:BlackRedMaroonOrangeYellowOliveLimeGreenAquaTealBlueNavyFuchsiaPurpleGraySilverWhite⟩$

$\mathrm{KnownColor}\left(P\,''Grey''\right)$

$\mathrm{true}$

$\mathrm{KnownColor}\left(P\,''Gray''\right)$

$\mathrm{true}$

$\mathrm{KnownColor}\left(P\,''Griy''\right)$

$\mathrm{false}$

$\mathrm{Lookup}\left(P\,''Griy''\right)$

Error, (in ColorTools:-Palette:-Lookup) invalid color Griy is not defined in this palette

The ColorTools[Palette][KnownColor] command was introduced in Maple 16.

For more information on Maple 16 changes, see Updates in Maple 16.