Collect skill points to unlock more bonuses at the Ship Vendor.

15 skill points:
Blargian Red
Orxon Green
Pokitaru Purple
Snagglebeast Brown
Qwark Green
Bogan Blue
Lombax Orange
Yeedil Yellow
Drek's Black Heart

16 skill points:
Special Insomniac paint jobs

18 skill points
Scoop Nose

26 skill points
Split Nose