Smartpak has a few custom saddle pad options, they have the Mattes Couture line as well as the High Point pads. I know for sure that Mattes has a nice orange they call "Terra", not sure about high point. BofB also carries the Toklat Classics III which are VERY nice, sturdy pads and can be full custom.
If at all possible, I would try to avoid going the seamstresss route yourself. It can be way, way more expensive than just ordering the darn thing in your colors... trust me, I've tried!