My black cat (Irving) has brownish red hair on his feet, legs and tail.

Im not sure why but my cats black hair has turned a redish brown color on the bottom of his feet, his tail, and the back of his legs. I dont know why his hair is changing colors. He has always been very small and I have a hard time getting him to gain weight, but he eats very well. I dont know if the color change is due to his health or if its just normal for this to happen.

Sun exposure can cause black-haired cats to develop a rusty tinge to their hair.  Some just have a natural predisposition for getting "highlights".  It's nothing to be concerned about, as far as I'm aware.

Thanks the3rdname. I was a little concerned. He acts fine. His hair is also thinning from the front of his ears to his eyes. Someone told me that some black cats just do that. I just wasnt sure if he had some kind of deficancy dont think I spelled that right. 

Hmm, is this happening all over his tail, or just at the back of it if it's standing straight up?

From your description it sounds as if it's the body parts that would be in direct contact with the ground if he was sitting. Has he sat in anything inside or outside that you know of? 

Its just on the back of his legs, and bottom of his tail I believe. I will look at it again after he wakes up. Hes a inside cat and im really careful about not leaving anything out that he can get into. He does like to lay in the sun in a window though.

How old is he? My cat has red fur in a lot of places especially if the sun hits him but he is also over 19 now. This is Scratchy inside at night and a camera flash...

Aww, what a cutie!  Love the expression, too.  He's like, Daaaaaaaaad, I'm trying to sleep!  

He is a year and 1/2.  What is wrong with Scratchy? Is that at blood pressure cuff on him?

Scratchy was probably close to 10 when he started to get lighter fur but 1 1/2 is a little young I would imagine but I could be wrong. They say a shortage of tyrosine in their diet causes a reduction of melanin in their hair and this is why they turn brown/red. This is also a sign of aging just like we get grey hair as we age. There are other things that can cause this so I would read up on black cats and tyrosine and learn about it. You will want to check with the vet before you make any changes because it can be so many things simple and complex.

Thank you for your input That Guy.