Yes, that'd be a good one. In the thread I linked to above I did samples of various kinds, but not black with beads.
The results were satisfactory enough for me since I planned on painting my roof white
My "unscientific" experience with them involved a 90 year old corrugated tin roof on a warehouse here in Houston. It was July or August several years ago and hovering a bit above a hundred degrees. The fellow who owned the building had just applied two coats (with brushes & rollers) to about half the roof on the inside. The unpainted part was untouchable for more than a second or so it was so hot. The areas that had been coated with the beads in latex paint at a 25% mix were barely above ambient inside air temp. Definitely a little below body temp. I was quite impressed. Like I said...not very scientific, but it absolutely sold me.