XD looks like a lot of us use purple! I do as well, though in varying shades. It makes the mares look more feminine ^^ All of my tack is black or brown because I drive, but I'm planning on buying new pads for the breastpiece and surcingle soon, and I'm ordering them in purple!
Her halter is 'wine' purple, and I have red, blue, purple, and brown leather leads. Lunge line and whip are purple too.
I agree that red looks horrible on most chestnuts, but my friend rides a mare named Shaniah, and Shaniah's colors are orange with a red browband, brown saddle, and red saddleseat. I think its cute.
And our QH gelding, Buddy- is ridden in all neutral colors except for his bright red reins! I find red to be a very attractive ACCENT color on chestnuts, so you might do well with navy and red!
But then again...Puddin' has a red headstall (she had a mahogany stained brown headstall but it snapped) and she doesn't look all that bad.
Everyone in your life is meant to
be in your journey, but not all of
them are meant to stay till the end.