I'd be in for suede. Anyone else?
If suede is a no-go I'll keep an open mind on a custom patina by Alexander.
Here's a great pic of Carmina burgundy calf in the sun (courtesy of ScottMC on the GF thread). I have these exact shoes and they are awesome. I'd say they are a little less red than this pic would indicate and super versatile (at least with suits, as that's all I every wear them with). It's a great color, in my opinion: