I've kept my hair bright red for about 2 years now and I've found that a good serum+oil has done wonders for my hair. I'm currently using a combo of two Bumble and Bumble ones, the Save the Day serum, and Hairdresser's invisible oil, which I apply after showering while my hair is still wet, before blowdrying. That, plus the occasional $2 in-shower moisture mask (the kind you can get in the shampoo aisle at walmart) has my hair feeling lovely and silky, and I like it cause it doesn't take long and and also doesn't take very much product so a travel sized bottle of the serum lasted me a solid 3 or 4 months, and I've yet to run out of the oil. They also smell amazing.