It can be very hard to distinguish red oak from white oak - it's not the color so much as it is differences in density and grain. I've had lumber supply companies try to pass off red oak for white; it's possible they don't know the difference or they have high school kids doing the sorting. The easiest way to tell is to see the tree it was cut from, I grew up in the northeast deer hunting and we all knew the deer preferred white oak over red oak acorns, so learned real quick the difference in the leaves:
white:
red:
The stock boards were white oak - you're right MM, it's more resistant and that's why it was used. Red oak is used more for interior work. With proper sealing and maintenance, you can have good results with both. White is typically harder to work with because of its density, but good results last a long time.
I thought about using a mahogany or teak when I had my first pair built, but the cost was outrageous and, once stained, I don't think there's that much of an advantage other than bragging rights.