My cat changes color.

Twice in the five years i've had my girl grey tabby she's changed colors almost before my eyes. Has anyone else seen this in their cats i don't think i was seeing things. I'll explain i had to move last january, It was to be about a eight hour drive my tabby girl was raised in the forrest of northen cailf she had no idea what a car even was .As we left on our trip un be-knowest to me a late winter storm moved in. My poor tabby went into a cat carrier and she did not like it from the word go, She yowled and meowed loudly and pretty much non stop . We then came to the snowed in pass that was closed till the storm let up so along with about twenty other cars and my cat who was hanging in there . the eight hour drive which i beleaved i could handle barely with my unsettled kitty now had turned into a twenty five hour marathon all in a car with my girl kitty. wow you say yeah, Anyways that nite in the car as i was holding, soothing, reassureing my kitty she looked different when i looked at her in the light i was stunned to see she was RED not red like an apple or fire engine but a deep almost a burnt amber or kinda brick red but she was defintly red. When we got to our new home she turned back to her basic tabby lite grey on dark grey on black markings after a few days all was ok. Very strange Anyone else seen this, The next time i saw this was just the other night she was outside and a coyote made a move on her luckly she got away but when i picked her up right after the same thing happened only she appeared to be a purple color not purple purple but again a deep deep violet color . Now i don't think i was seeing things what do you guys think? Here's my take I beleave when a cat gets really disstressed and it can't retreat from a situation or precieved danger they will change color to blend or hide.The color comes from some type of chemecal inbalance brought on by the disstress .Like when they puff up double in size to appear big and ward off its attacker. Instint brought on by fear .I would love to hear what you folks think.