Slim Tcl Expression for color, vector, point

Color and Point Functions
rgb(r,g,b), rgbi(ir,ig,ib)
Allow the specification of color (vector) parameters. r,g,b in the range [0,1], ir,ig,ib in the range [0,255].

hsv(h,s,v), hsvi(ih,is,iv)
Allow the specification of color (vector) parameters in the HSV color space. h,s,v in the range [0,1], ih,is,iv in the range [0,255]. Note that this will immediately convert the hsv values to rgb values.

xyz(x,y,z)
Allow the specification of point (vector) parameters.