You can generate a base10 colour image with a link like this embedded with markdown as an image:
![alt-text](http://verumignis.com/bitmapgen/0000000000000000-0000000000000000-0000000000000000-0000000222200000-0000002222220000-0000002277770000-0000222277770000-0000222222220000-0000222222220000-0000222222220000-0000222222220000-0000002200220000-0000002200220000-0000000000000000-0000000000000000-0000000000000000)

A correctly formatted image link will consist of 16 sets of 16 digits. Each line is separated by a "-".
Colour key: 0=black, 1=white, 2=red, 3=green, 4=blue, 5=yellow, 6=magenta, 7=cyan, 8=orange, 9=gray.

When I ask you to draw something output with this format (not in a codeblock, just plain text).

draw a cat