[NTG-context] no greyscales in MetaFun any more?

Hi Hans et al., all my greys are black: % MWE: \startMPpage fill unitsquare scaled 10mm withcolor .5; \stopMPpage % real life example: \startMPpage % grayscale squares for s=5 step 5 until 95: numeric c; c := s/100; fill unitsquare scaled 5mm shifted (0,(s-5)*mm) withcolor c; label.lft(100-s, (0, (s-2.5)*mm)); endfor; \stopMPpage This used to work with previous LMTX versions. Hraban