A few examples of what you can ask Wolfram|Alpha about:
get information about a color
compute properties of a named color
specify an HTML color
query a specific property of a color
get information about a color tone
compare colors
specify a color using red-green-blue (RGB) values
specify a color using XYZ values
specify a color using CIELAB values
Related Colors
complementary color
find a color triad
find a color tetrad
find a nearby brand color
explore the properties of colored light
find facts about the colors of light
compare colors of light
Sets of Colors
investigate groups of colors
examine the color space properties of a set of colors
compare sets of colors
Color Conversions
convert a hexadecimal RGB color to HSL representation
convert a named color to CIELAB representation
Paint Colors
specify a paint color by brand and name or number
compute the blackbody radiation color for a temperature