And just for a nit - lines can have all kinds of attributes besides
colour - thickness (i.e. bold), solid/dotted (i.e. italic), wavy (i.e.
font face), tapered (i.e. slant), etc. I really don't think colour
should be considered a special attribute just because it can apply to
things besides text.
Of course, but we're not voting about those semantics. We're voting about the degree of control we want to have via the UI's input capability.
Your vote advocates that, for one case, the radiance-adjusting controls should be commingled with the shape-adjusting controls.