[NTG-context] Passing colors to Metafun and TeX's bitmapimage macros

Hi, list! I want to know if there's a handy way to pass predefined colors, either RGB or CMYK, e.g. those in svg or crayola, to Metafun's bitmapimage. Say, something like: \startMPpage % svg's gold definition draw bitmapimage(2, 2, "ffd700 ffd700 ffd700 000000") scaled 3cm; \stopMPpage using "gold" instead of its definition so that I can set bitmap image colors by name rather than numbers. In a similar vein, I wonder if something analogous is possible for ConTeXt's \bitmapimage macro. Thank you in advance. Cordially, Jairo