Best shampoo and conditioner for colored hair

You should try and leave it as long as possible really. I wash my hair about every 5-7 days, occasionally longer. You can start off slowly and try and leave it longer and longer. It's better for your hair and scalp in the long run.

The ideal is to do conditioner only washing and use very cool to cold water. That's not possible for everyone though, especially if you have very straight fine hair. Finding shampoo that doesn't have Sodium Lauryl Sulfate also helps, it's milder. But definitely stick to using cool to cold water.

Here's a great thread with lots of ways to help keep your hair vibrant. http://www.hairdyeforum.com/index.php/topic,11009.0.html

I'd only wash dyed hair once a week, conditioner-only or minimal (preferably SLS-free) shampoo then conditioner.  I mean literally a drop of shampoo, just enough to wash the scalp and rinse through the lengths.
I do mine in the shower usually so warm water but finish with a cold-as-I-can-stand rinse.

Hot water and suds are the enemies of dyed hair  😉