How long can you keep dye and developer for??

Hello! I've had a bottle of dye (Loreal Excellence Professional color) and a bottle of 30 volume oreor creme developer (peroxide) for about a year. The dye has never been touched, but the developer has been used once. Are they still good or do I have to throw them away? I developer is a large bottle that's been sealed tightly, but like
I said it was used one time approximately a year ago.

Thanks.