I spent a lot of time mixing and thinking about the grey background knowing that this would make or break the painting. It couldn't be too warm or too cool. I did adjust it with subsequent color mixtures so that it would be as harmonious as possible with the rest of the painting.
I also used a yellow/purple palette which means there was no true red available. I mixed my reds with permanent rose and cadmium yellow deep!
"Red Tablecloth" 2 1/2 x 3 3/8 inches, oil on board