Useful when mixed with black for details. Red Ocher - do not breath the dust. The modern name for Sinopia, the color used in the Renaissance for painting flesh tones. Remarkable for high lights. Vermilion Poisonous - do not ingest or breath the dust.
True vermilion is quite beautiful but expensive and has questionable permanence.
The modern substitute is more permanent though slightly more orange in color than the original. Cadmium Red Toxic Permanent but tend to be garish compared to earth reds. When mixed with water they can generate a strong, almost putrefying smell. A pale color with good tinting strength. Very useful for underpainting and laying in solid green tones.