On 2013–04–19 Mojca Miklavec wrote:

> Dear Hans,
> 
> please consider the following example in MKII:
> 
> \setupcolors[state=start]
> 
> \starttext
> 
> \startMPextensions
> a := \abc;
> color b;
> b := \MPcolor{currentcolor};
> \stopMPextensions
> 
> \startuseMPgraphic{bla}
> fill fullcircle scaled a withcolor b;
> \stopuseMPgraphic
> 
> \def\abc{3cm}\color[blue]{\useMPgraphic{bla}}
> 
> % Nice small black circle
> \def\abc{1cm}\useMPgraphic{bla}
> 
> \stoptext
> 
> 
> I still don't know how to reproduce this in MKIV.

Use \startMPinitializations instead of \startMPextensions, it's
global to all MP instances, though.

Marco