It is my understanding that many Native Americans see animals that are white, mostly those that are not normally seen in that color as sacred. Scared in the senses, that they are white makes the animal more visible and makes it more susceptible to its enemy, for it to be living indicates to them that they are special in some way. They must have been very clever and cunning to be able to survive without detection because of there color. Many Native Americans believe it is wrong to kill them in a hunt.
The white buffalo is considered holy among the Lakota...
Now as to you animal guides being white in color, it sounds like you are referring to their natural color.
White is symbolic of;
Purity, Cleanliness, Truth, Innocence, Light.
How does the color relate to who you are?