Wrap the stand in cabinet grade plywood, add doors if you want and stain with a dark walnut or other close to black stain. Staining real dark still shows the grain and would match the tank.
Sorry but I'd paint it black. Black lights, black tank n diff color stand? The stand takes away from viewing the fish and it's like having a Black TV with a red stand. JMO
I am usually a stain fan but in this case I would paint it black to match the tank.
The only problem with black is that it will show dirt very easy compared to stain.