You can back up your save file. It's named "game.sol" and it's located here:
C:\Users\*YOURNAME*\AppData\Roaming\Stencyl\SkateRide
AppData folder might be hidden (I think it is by default)
You might already did this, but just to be sure, can you re-download the game, delete old SkateRide folder, unzip it the new one and test again? Progression will stay, only Skater's color will reset. (btw, you still got problems with color not changing?)
thx