Hi,

In the MWE below I define an rgb colour, myColor1, using random numbers for the r, g and b components. I then use it to fill a unitsquare the size of the page, which works as expected. In the loop that follows I then use the defined colour, myColor1, along with white and the variable r to create shades of myColor1 as in the MWE below. However, myColor1 is not recognised in the loop and seems to be replaced by black, although if I use a predefined colour, in this case BurntSienna from the crayola collection, it works as expected.  I have tried a number of ways to get this to work as shown in the code but without success. I would be grateful for any suggestions.

Best Wishes

Keith McKay

%%%%%%%%%%%%%%%%%%%%MWE%%%%%%%%%%%%%

\setuppapersize[A4,portrait]

\usecolors[crayola]

\starttext

\dorecurse{10}{

\startMPpage

StartPage;

\definecolor[name="myColor1", r = uniformdeviate(1), g = uniformdeviate(1), b = uniformdeviate(1) ] ;