When can I use perm lotion/hair dye/chemicals on my hair after hairline transplant?

Think about what your doctor may say if you follow someone else's advice and you end up with a bad result.The Internet may confuse you more with conflicting answers.  The only correct answer in your case is what your doctor (the one you paid a lot of money and trusted) recommends.  

We often dye the hair immediately before the transplant.  I would wait until the skin is well healed before you resume dyes.  7 to 10 days should be fine.  If the dye irritates the healed wound, stop dying for another week.  

I always recommend four to six weeks to wait before using any chemicals on your hair after a transplant.