Whether you have a blue Chihuahua, or one of another color, all Chihuahuas need the same care. Many people might have the idea that blue is a rare color for this breed, but it is actually quite common. 
The colors of this breed of dog include gray with dark streaks, blond, black, brown and fawn, which is a blend of brown and blond. Blue Chihuahuas are very sensitive to the heat, so if you live in a hot climate, you should keep the dog in an air-conditioned interior, and take it for walks in the evening when it is cooler.
You should bring your blue Chihuahua to the vet for its vaccinations, and for yearly checkups. This will help you keep the dog immune from certain diseases. The vet will also be able to give you excellent information about using flea control products, and about having your pet de-wormed. The main ingredient in the dog food should be meat because Chihuahuas, like all other dogs, need a substantial amount of protein in their diet. The dog food you choose should have at least 30% protein and at least 20% fat. Read the list of ingredients on the package label to make sure that it contains these proportions, and that it also contains no more than 4% fiber. You also need to feed your pet small portions about 4 times a day, rather than one large meal.
When grooming a blue Chihuahua, you should use a dog brush with soft bristles. For short haired dogs of this breed, you can wipe them down with a soft cloth, but if you have one of the long haired dogs, you will need to brush the coat on a daily basis. Be careful not to bathe a Chihuahua too often - once a month is what veterinarians recommend. When you do bathe your pet, you have to be careful not to get water in its ears because this can lead to ear infections. There are some excellent odor removal products available to keep down the dog odor between baths.
Blue Chihuahuas need daily exercise. This doesn't mean that you need to bring your pet on a long walk every day. 
These animals usually have short bursts of energy, so you can have very active play inside or outside to supply it with its daily need. When you do take the dog for a walk, a dog harness is better, because you won't have to worry about the collar being tight. If you do decide to use a collar for attaching a leash, you shouldn't pull on the leash because extra force could damage the dog's trachea.
A blue Chihuahua needs to be trained and socialized at an early age. The easiest way to do this is through obedience classes, because it will learn how to behave and get used to being in the presence of other dogs. You do need to be gentle when training, and give your blue Chihuahua lots of love and attention.
