There ought to be a convinent way to describe color in terms of tuples in standard color spaces. (RGB, CMYK, HSV, HSB, CIE, etc)
Something like {x1 has RGB color of x2 redness, x3 greeness, and x4 blueness (where x2 - x4 are in [0, 1]).} Suggest a set of lujvo.
judryska "color-coordinate" {x1 is the color specified by position tuple x2 in color space/system x3 (default: RGB)}
le tsani ka blanu cu judryska li pimureso pi'e pibinoze pi'e pa la rgb
(RGB values convinently provided by the X11 Consortium.)