Here are some oil paint swatches. For each paint, the pure color is on top and that color mixed with white is below. There is no way for me to take a picture, post it on the web, and have you see it accurately on your computer monitor. But this gives some idea of what the color looks like. I find this to be a useful reference when I’m searching for just the right color to add to my core palette.
Top row (left to right): Red ochre (Williamsburg), Italian burnt sienna (WB), vermilion genuine (Doak), yellow ochre (WB), Italian raw sienna (WB), raw umber (Old Holland), burnt umber (WB), terre verte (WB), ultramarine blue (Studio Products), German earth (WB).
Bottom row: Florentine lake (Doak), Bohemian green earth (WB), Tuscan red (Studio Products), Pozzuoli earth (WB), Indian yellow (Doak), Fra Angelico blue (Doak), Alger blue (Doak), transparent blue oxide (Doak), milori (Prussian) blue (Doak), indigo (WB).