Sorry Hunter, welcome to the madness of BYAP
Gravel gets hot no matter what colour unfortunately and we all have had the problem of small plants wilting during summer from the heat rising off the gravel
The best way to minimise this (if using gravel) is to shade it, this can be done by:
1) shadecloth - to reduce the heat intensity, the gravel still gets hot but not to a "killing" temperature
2) plant plentifully so that the gravel is covered in shade
You can lay the shadecloth on the gravel and cut holes in it to put the plants in or build a green house