Bay or Blue Roan?

On this, this is correct as far as I know. If a horse is both traditional roan and tobiano you will never have the horse homozygous for either roan or tobiano (all in the same horse that is).

Well, learn something new every day. So every color can have roaning?

And I didn't really think she was fading black, as the brown on her nose is there year round, doesn't lessen at all during winter. It was just more curiosity.

I see a classic blue roan!

http://equine-color.info/gallery/v/white/roan/

This page has a few pics of different roans, however they only have the roan on 'normal' base colours.

Looks like a blue roan to me.

It's the brown phenotype that is making her look blue roan. Blue roan is a black based roan. A brown horse can be very dark and look black over most of it's body, but the brown on the nose is a dead give-away. She is a brown based roan. It doesn't mean she is any less beautiful.

Here is another brown based roan:



As you can see, blue roan in appearance, with red on the muzzle.


Here is a black based roan:



There is a clear difference.

This looks more like a brown roan to me. I would have said that the browning on the mare's nose on the top picture you posted, Chilla, was just sun bleaching. But I could be wrong. I guess I do see some brown flank hairs, too. Btw, what breed of horse is that? Paso? Beautiful!

To me, that horse is blatantly bay roan. Brown is usually almost black with only the nose and possibly flank area being a shade of mahogany to indicate the horse isn't black, hence the body often IS still black and why you'll have a "blue roan" with a brown nose - because that horse would look almost black without the roaning anyway. Of course you can get slightly lighter browns, but they're still far closer to black then they usually are the rich mahogany shade of bay.

That one is a bay roan :) Sun bleaching doesn't tend to happen on the nose IME, and the OP has also said that the amount of red doesn't change with the seasons.

And yes, a Paso in my pic.