I need some advice, any hairdressers or people who know a lot about hair?

I got my hair dyed dark brown in October as it was bleach blonde. The hairdresser told me it would need to be dyed a couple more times before it holds. Now its really light and I'm not sure if I should get it dark again as its summer and it might get lighter again. How do you stop your hair getting lighter in the sun?I need some advice, any hairdressers or people who know a lot about hair?
You can't, that's the way it is. I have dyed my hair blonde once, but I could see my brown curls coming up. I decided to keep my hair dark. But I would say wait until it gets cooler out , near the end of the summer, that's when it's best to get it dyed. If you have a pool or something, wait until its colder, you don't want your hair to turn green.I need some advice, any hairdressers or people who know a lot about hair?
if you keep dyeing your hair it will fall out but you might want to stick with dyeing your hair a couple of times before you have it change the color of your hair style and that as you get older you will have your hair change different color's every time you get older and older.trust me it will change because that is what happen to my hair.
Hats, bandanas, scarfs, only physical barriers help to block the sun's color fading rays.
YOU CANT.
it's not possible....wtf?