When gardening on a retirement income, it is necessary to save where ever possible. These are almost entirely containers with soil not more than a year old. My potting soil is a commercial nursery mix, bark based with no peat. All recovered potting soil is combined and refreshed with the addition of 30% fir bark,(available free)a teaspoon of 18-6-12 time release fertilizer per gallon, and a tablespoon of dolomite lime, per gallon. I only use it for containers of one gallon or larger. New nursery mix is used for 4 inch and smaller containers. For those containers destined for several years with the same soil, I only use one of Al's(taplas)mixes. Al

I would say it has less to do with the pot color and more to do with the soil drying out / heating up too much. If you absolutely have to put pots in full noon sun, mulch heavily. You could try shading the pot base maybe with a "tree skirt" that wraps around made from burlap, shade cloth, or something like that.

Yes, add new soil.

I change up a large painting in my living room, from Spring/Summer to Fall/Winter, My mother inherited an original oil painting, from a friend of hers who was a very talented artist. I in turn, inherited it from her. It's a painting of the artist's log cabin and surrounding property in Vermont. He painted it in the late afternoon in Winter. The sky is crimson and full of clouds of varying shades. The cabin is covered in snow and violet smoke is coming from the chimney. The trees and field are also snow covered, so this painting captures the beauty and essence of Winter. I also have an oil painting of a beautiful scene in Summer. It is of a terra cotta terrace overlooking the Mediterranean, with large pots of vividly colored flowers, and Wisteria hanging from the arched roof. A hilly coastline, which is dotted with white houses with tile roofs is in the distance. It's very colorful and makes me feel like I'm in a little villa in Greece, whenever I look at it. As I only have room to display one in my living room, I display the Summer painting every April and change it to the Winter one every October. I hang the 'off season' painting in my bedroom, so it can still be enjoyed!