If you want to use a color for the text in the Desktop Info Panel of DeskScapes 11 that is not available in the preset colors, open Regedit and go to the following String and change the Data Value to your custom color.
Computer\HKEY_CURRENT_USER\SOFTWARE\Stardock\Deskscapes\DS11.ini\Clock\ColourOveride
IMPORTANT! This value is Decimal, so you must first convert your custom color to a Decimal value. (If you use MS PowerToys, the color picker module includes a Decimal value output, or there are many convertors available online.)
As always, make a backup copy of the Registry before you make changes!