The only way to get your parts to truely match is if all of them are anodized at the same time from the same batch of dye and is all the same grade of metal.
Just to clarify...annodizing is not a coating in that nothing is sprayed on or coated on the aluminum. Annodizing is actually an aluminum oxide crystal grown from the aluminum of the part being anodized. After the part is anodized it is then dipped in a dye for color. The dye settles in the cavities of the crystal to give the part color.