Raised Bed Colouring?

Hi all!

Planning out a new potager style kitchen garden space in an area where I'll actually be going through every day (hello zone 1) and should be better designed than what we currently have (incorporating watering most likely with soaker hose setup, beds sitting in a better direction for the sun, etc). I'd like to have raised beds and have a pallet full of black roofing tiles which I think would work perfectly, but wondering if there's an issue with the colouring and them getting too hot in our sun and drying the beds out too quickly? We're middle temperate/moving toward Mediterranean, winters around 5-15C, and summers can get up into the high 30s with the hot Australian sun. Another option for still using the tiles is to have the black painted side facing in so the grey congrete faces out, but not sure if there's chemicals etc on those sides that could leech into the soil if they're pressed up against it.

All thoughts and ideas appreciated! Worse comes to worse we have plenty of scrap timber around I could use, just wouldn't look quite so pretty :D