Just FYI: The Spectrum color match is also not perfect.
If you order the quart and pay the enormous fee, it is shipped with a slip of paper that says you will likely still need to color match it.
What I got from Spectrum was just barely acceptable for matching original gelcoat that had been covered up since the boat was new.
If you are going the DIY route, I went through several kits on different boats and have found the kit from RAYPLEX has the actual tones you need to get a good off-white match if you have the eyes to do it.