I have tried flea/tic sprays, shampoo, conditioners,

Are you asking why the skin is a different color than your dogs hair?
Can you please give us some more information?

There are a number of things that can cause your dogs skin to discolor, anything from parasites to allergies. If it is fleas, your best bet is to get a treatment from your vet instead of using OTC medications.

Has the dogs skin changed color recently?

If you can provide us with any more information, it will greatly help us in helping you.

tlgrams, the discoloration of the hair & skin comes from your dog's saliva. When a dog licks excessively, the hair will turn a rusty brown color and the skin usually turns red and eventually dark brownish/blackish.

Aurora Bell is right, you need to see your vet if you haven't already done so. Too many baths & over the counter tick/flea sprays are not the solution and usually make the problem worse. I have found when there is excessive licking & discoloration it is usually caused by allergies. But, every dog is different. Please don't give your dog any more topical treatments and take him/her in for an examination. Good luck.