As some of you know, John's dad's cat lives with John and I. We pretty much think of her as our own now. Anyway, she is solid grey (or blue, or whatever the proper term is). I've noticed the past few months that the fur on her sides are turning to a rusty brown color. I thought that maybe she was just dirty since I was told she had only ever had one bath in her life, but after a bath and several baths with baby wipes, the rusty color is still there. She is approximately 6-7 years old but no one really remembers, she's definitely not any younger than 6 but could be older. Could it just be that she's getting older?

I think it's probably just her aging. Wickett's color has changed quite a bit and he's only 3! As a very small kitten he was chocolate with black points. At about 6 months her went all black and about a year ago I noticed his arm pits are going grey. I mentioned to the vet and he said it's only going to turn more grey as he ages and I have noticed the grey patches slowely getting bigger.

Could be from washing herself. I know that white cats can turn yellow when grooming a lot over time. That might be part of the problem.

Or its from the cat sitting in the sun for long periods of time (does this cat go outside in direct sunlight?)

Could be from washing herself. I know that white cats can turn yellow when grooming a lot over time. That might be part of the problem.

Or its from the cat sitting in the sun for long periods of time (does this cat go outside in direct sunlight?)

She doesn't ever go outside, so it's not from sunlight. It could be from grooming though, I never though of that.

Yes, aging. We had a blue-gray cat... instead of going gray, his hair turned rust-colored in places as he got old.

My old Cat Coco is half Siamese but she is black and white. Her fur is turning Reddish Brown because her age.

Chloe's fur is changing too, but she is only 4 months old. A month ago, she was a dilute tortie (with white on her chest), the peachy parts were very well blended with the grey. Now, the peach on her back is fading and she's becoming more grey.

We had one that was that dark grey/blue colour and she definately turned a brown/rust colour as she got older. I wouldn't be worried at all :)