Testing is an excellent suggestion. The effects of color combinations might surprise you. For an example if the lesser color adjacent to a dominant color contains a small amount of the background (dominant), the background will take it away. Confused? General example: if you mixed a small amount of orange into white, slightly tinted were it looks peachy by itself in a cup, and put it on the orange, it would come off as white.
I used to hand letter trucks with lettering enamel (mostly OneShot) and I would mix background color into white when white was requested. Red truck: red into white looked pale pink. Blue truck: pale blue. You would swear the lettering was bright white.
In my youth I attended an art college and received a rare A+ grade on mixing colors. But truth be told I'm the last guy you want to ask about color choices. I have spent entire days mixing, testing and deciding!
At least you decided the colors and the two tone.