Yes it is very likely I didn't add enough coloring, the label warned "NOT" to exceed 1 tube per 4oz of gel coat, which must be really easy to follow if you're willing to risk a $20 tube of gelcoat to try ($50 kit with 2 x 2oz tubes and a bunch of coloring I'll never use).
I tried the coloring but again unless you're willing to commit to mixing up a bunch of this at once your ratios are very volatile. I added the smallest pinch of yellow that I could and it turned the mixture creme.
I did use that testing technique though. Actually I wasted a fair amount of the gel coat when I determined I was satisfied with the color and happily spread it all on, forgetting I hadn't added the hardener yet. Most of it scraped off but the rest I wiped off with a cloth and acetone.
My concern wasn't really the tones though (I read so many times that matching was so near impossible that I pretty much never had much hope short of luck) it was more about making a smooth surface for it to adhere to, and then once I realized that the color was going to show through, I wasn't happy.
The kit says I can add the gel coat without ANY coloring if the dent doesn't go through the gel coat. I'll have to give that a try tomorrow as well. I'll also try lightly sanding a thin line in the middle of a gash to clean/smooth it, wipe with acetone and see how that works.
Depends on how main patch fix goes
PS: Yes "grand" is the appropriate word for it. I swear I saw the west marine manager light up with joy when he saw my car drive in for the third time today. I really prefer to buy my stuff through amazon (save a lot) but for short notice stuff (like today's Evercoat Forumla 27 filler) I have to spend the big bucks. They are definite the convenience store of the marine world