A little piece of "if I were doing this map .. "
I'd use the sun or a bright earth. There would be a more organic colour scheme. I'd trace the symbols into crisp vectors. Trace from photographs if you are really concerned about using someone else's 'art' (even though tattoo art is perfect for this!), since your finished product will really be your own, and not look like the original photo.
The top right corner - those would be in seasonal colours instead of the same colours as on the playing board. As an idea, lightly I stuck a seasonal colour radiating from the centre sun. (yellow in this case) They can still be yellow-green-blue-red.
It's confusing to see Capricorn, Virgo, and Taurus in green on the play board, then to see Aries, Taurus, and Gemini in the bonus area. If I was playing the map, I would probably skip reading the names and just assume I'd get a bonus for holding all the green, and be disappointed when it was otherwise.
When choosing a font for your signature, choose something in the same theme as the rest of the map. Maybe there's a Star Trek font you can use to make it different yet in the same family.