Kittens are born cute and cuddly, and most have their basic adult coloring as well. Some breeds, however, change their coat colors as they mature. A color change might also be signalling a health issue, so keep a close eye on your kitty if she's changing colors unexpectedly.
Eyes
Newly born kittens have the prettiest blue eyes you've ever seen -- as soon as their eyes open, that is. However, most cat breeds don't keep blue eyes. By the time your kitten is 3 months old, she should have a new eye color, usually a shade of green or gold. Some kitties that have naturally blue eyes as adults, such as Himalayans, might have reddish or pink eyes when they're born.
Normal Fur Changes
A few feline breeds naturally change their coat colors as they grow. Siamese cats, for example, start out white as kittens and grow into their darker points. Persians come in a variety of colors, some of which -- such as the shaded blue-cream coat -- can change as the cat grows up. They normally stick with the same color scheme, but the hair might appear to be two-toned, with blue on the tip and cream closer to the body, as the blue and cream areas switch. Some kittens, especially those that are a red or a smoky color, can be born with faint stripes similar to tabby markings. These are called ghost markings, and they usually fade by the time your kitten gets to be about a year old. They typically mean your cat has a bit of tabby in her, although the gene isn't dominant.
Health Issues
An unexpected change in your kitten's color can signal a health issue, so always check with your vet. If your kitty is licking a certain area more than others, the saliva can change the fur color to a reddish tinge. This over-licking might be a result of pain in that area. Patches of fur that change color might mean the skin underneath has changed color, which could be nothing more than a strange pigmentation change or could be as serious as a cancerous tumor. Changing fur color over your feline's entire body could signal a systemic problem, such as kidney or thyroid disease.
Diet Issues
Food allergies can cause a bunch of problems for your kitty, including changes in fur color. These allergies are often discovered in kittens as you change foods to match their growing needs. A lack of amino acids such as tyrosine or minerals such as zinc or copper can cause dark coats to look faded or slightly red. Foods high in omega-3 and omega-6 fatty acids can give your playful pet a shiny, fluffy coat. Tell your vet about any coat changes and ask for dietary recommendations.