PPC (errr, I don't think I got the name correct) but you can go the local car paint shop and ask them for their leather dye and the proper procedure to the use their products.
Ruffing up the leather depends on the product you will spray it with.
Other times you'd need a primer coat to do the same as sanding.
As for primer colors that will depend on your top-coat.
Once again, check with the shop for the proper product usage.