The other day I did something really interesting. I ran the image of the board through colour blind filters.
The colour blind site I used was called Toptal, and it gave me the option of looking at a website (this one, obviously) using different filters. In one filter, the green and blue looked grey and blue, in another it looked faintly pink and blue, and in a third it looked like different shades of green. The picture above is what a protanopla (red-green) filter does to the colours.
Luckily, the colour contrast was clear under all versions – which is what matters!