I've been making "stained glass" dice ever since I got blank inserts for my molds. The trick is to leave some panels clear so untinted light can show through.
This time I'm using some inserts from Druid Dice that have geometric patterns in them. I've painted the lines in silver and am using sharpie markers for the tiny panels.
I have found that, while it rarely happens, it is good to clear-coat these inserts to prevent any excess ink from coming off in the molds.
I will likely use a pearlescent white for the numbers, though may go for sage green if the white isn't readable.
These are inserts. They are the same shape as the dice, but smaller by the depth of the numbers so that they are held in place by the number indents.