Have you tried the X2 Baby Bass colorant? The color plates shown with the color are not a super good representation of what you'll get, but I have the color and think its pretty close to what the Yamamoto baits look like.
Try this4oz. ESS Plastisol 2 Tbls salt2 drops Do it X2 Watermelon1 drop LC black1 dash .15 black flake1 pinch .15 gold flakeI was playing around with this today and it is spot on.Hope that helps.