*The pansy IS NOT a plant that likes hot weather. Out front we have
four
pots of pansies, two light grey and two black. They get equal sun,
equal watering. The pansies* in the two grey pots are still doing well
but the two black pots have lost the pansies.
Could this be because of the color of the pot??

It sure is, Tom. Black pots absorb the heat just like black hats and
clothing. The soil can get so hot that the roots are cooked.

*These pansies were of the big diameter bloom variety. And they were,
but as the summer progresses, the blooms are now your run of the mill
size. I wonder what caused this change??

The loss of vigor from the age of the plants and the heat. Usually my
pansies are about the size of small Violas by the time I pull them out
the first week of July. They are replaced with summer heat lovers:
portulaca is a good one to replace pansies.

Emilie
NorCal