Render colours not accessible without WPF dependency

[david-pfx]

The immediate problem is to access the standard colours in Rasmol and Jmol, because to include the Render module also brings in a dependency on WPF.

There are other parts of the Render module that would be useful to those (like myself) who with to depict molecules using render technology other than WPF.

[k-ujihara]

I understand the problem. I am also facing the same problem with accessing Excel. However, I won't fix it. Sorry.