6-7 weeks into flowering and my leaves are turning red,yellow golden bronze.Why??????

so i have two NL plants that i aquired as clones. Both were in the same pot so i grew them into mothers and flowered them after taking a new batch of clones off of them. I know that yeild and vigor will be hinderd do to the fact that the two plants are fighting for root room. so my question is why are my leaves turning red,golden,bronze color? is this just the end of the flowering cycle or is this a different issue?

I forgot to mention that they are about 6-7 weeks into the 12/12.

You will be fine. The plant is using up all energy in the plant leaves to develop its bud. The leaves die off as the plant finishes it life cycle. Pics would be nice. At 6-7 weeks, you are very close to finishing with NL, as it is a fairly fast finisher.