Hi Myrna- I color my grays too, so I do get that. One thing I can tell you is this; since I have eliminated glycerin for the summer, my color seems to last longer! I have read that glycerin pulls color out of hair, and didn't pay much attention to it until I noticed it as a side effect of not using glycerin anymore....
I also just wanted to say something about you not using leave-ins anymore- from my understanding with low porosity hair, your rinse out is not really ever absorbed, so moisture that stays ON the hair for longer, is more important. (Per KathyMack)
2C-3A/ Coarse/ Normal to high porosity/ SW Florida
Cleanse: *CJ Daily Fix, AIA Coco Cowash, Trader Joe's TTT condish, Shea Moisture poos
Condish: CJ Smoothing, Curly Kinks Renew, Darcy's Pumpkin, *CJ Curl Rehab
Enhancers & 2nd day products: *Okra gel or FSG, Uncle Funky's CM, CJ Pattern Pusha
Gels: MGA sculpting, Giovanni LAN, Spiral Solutions FHG, LALSG, *JC Spiralicious