I use the "standard" non-X2 Colorants (I do have X2 Motor Oil), and as Mr. PJM has said in the past, count the Fluorescents in 10's, not 1's. I use the Fluorescent Chartreuse in a color I call "Fawnky Chicken" (12 oz.s plastic with 1 Pinch of Red Pearl Powder) that uses 120 drops of non-X2 Fl. Chartreuse. X2 Colorant definitely seems to excel here. Try going to 80 drops, or 100 or 120 drops, and see if that doesn't melt Your monofilament.