Don't worry man, they are supposed to turn orange... it means the plant is ripening. You probably thought they turn orange AFTER harvest, but this is not the case. about 90% of pistils will be orange at harvest.

Also, humidity SHOULD be low during flowering. it prevents bud rot. don't be surprised if you leaves start looking unhealthy in a few weeks either... its perfectly normal for them to wilt right before harvest.

If at all possible, try and switch your MH to an HPS. HPS is better for flowering, MH is better for vegging.

Good luck :thumbsup: