[NTG-context] [ scaling colors ]

with the environment of \startMPcode you can scale a color with a factor like 0.25red and 0.5blue But this not seem to work when you define a color yourself first definecolor [ name = "MyColor", r = .5, g = .25, b = .25 ] ; fill fullsquare xyscaled (40mm, 15mm) withcolor "MyColor" ; fill fullsquare xyscaled (40mm, 15mm) shifted (42mm, 0mm) withcolor 0.5"MyColor" ; What would be the correct way to scale self defined colors? .F