I've been coloring my hair a deep red for over 3 years now. I've tried a lot of different products to keep my color fresh. I tried Pureology and I saw color go down the drain. It also made my hair feel like straw.
I made a decision to only use sulfate-free shampoos. Sulfates are harsh and strip red like nothing else. You can find a lot of sulfate-free shampoos in health food stores. I like the Giovanni & Ecco Bella lines but there are others.
The Paves line at Walgreens is sulfate-free. It doesn't have the best scent but it also doesn't last. You can find them on sale BOGO Free.
I personally use Kenra's Platinum line for thick/coarse hair. They make 3 formulas; fine/thin, medium/normal and thick/coarse. The thick/coarse conditioner (reconstructor) that goes with the shampoo has shea butter and make my hair so soft and shiney. And it smells like strawberries, so delicious. I get mine at Trade Secret when they have the line BOGO 50% off.
Also, the Jonathan line at Sephora and on QVC is sulfate-free. I tried it and hated it. That's just me. At least with QVC you can return them if you hate it.
Oh and color depositing conditioners are great but I don't use them that much. I always forget to grab gloves before I get in the shower and I hate how they stain my hands and nails. I've used ones from Goldwell, Aveda and Graham Webb. They all deposit some color but when you get close to your next color, nothing can really make that much of a difference IMO. And, I wouldn't waste money on a color depositing shampoo. THey don't deposit much, if any, color. The conditioner is where the color payoff lies. HTH!