(Previously posted on September 24, 2008 on the Blackberry Lane Studio Blog.)
This might look like a very white tobiano, which would explain why the bottom of her tail is so dark. Tobianos, even very white ones, tend to do that. But that’s not a tobiano tail, because her pattern doesn’t include her tail.
She’s a grey tobiano, and her hindquarters are colored – not white. So that’s technically a grey tail, and grey tails are not supposed to do that. Grey tails typically lighten from the bottom up, rather than from the tailhead down.
You can see her tobiano pattern a little better here. She’s also a little unusual for having greyed out so quickly; her owner said she had just turned five. She also said that she was born roan, which might explain why her body greyed out while her tail remained dark. It certainly was striking, and I noticed a number of onlookers comment that they had not seen a grey horse with such a dark tail before.
[June 6, 2011: Just a quick note. There were more photos with oddities that should have been posted to this series back when it first ran, but shortly afterward the computer where they were stored crashed. It's a shame because that particular show had a lot of oddities!]