They do have a coat supplement especially for palomino/dun/etc. horses, BUT it will show up in drug tests if you show. So...
The sun is probably part of the problem, most fly sheets have UV protection. Then you can try feeding a show bloom supplement, or coat one (I have used Grand Coat, but it's a tad expensive). More correct work will help too.. she's got a pot belly on her ;) Does she get grain at all?
Dressage in Jeans
- My blog with dressage tips for happy, relaxed horses, specifically for those who ride dressage in western saddles, no saddles, cowboy boots, or jeans. ;) Also now with cute pygmy goat pictures! :P