I've been wanting to paint more portraits outside using natural light, so I recently set up a mirror and sat myself down for a self-portrait (well, I was standing, but you get the idea). My goals lay more in exploring the new color relationships and what they convey than in trying to get a 'likeness'; however, with enough time, the individual will come through with the right shapes and spots of color.*
It was definitely hot out - my thermometer read 100F in the shade - but my goal wasn't bragging rights for painting in extreme temperatures; I wanted to use color to convey that heat. The darker and warmer reds in the shadow on my face are (relatively) darker compared to the greenish-oranges in the shadow on my neck, and the cooler pinks and violets around my cheekbones are lighter than those reds; still, while more 'colorful' than one might expect, when taken all together they should hold a sense of form and create a sense of light. This kind of information is lost in a photograph, hence the necessity of painting in the heat.
A little side note about my color: I've had people ask how I categorize myself: would I consider myself an Impressionist, Expressionist, or lately, Fauvist (what, no Romanticism?). While I admire artists from those movements, I don't feel akin to them. And while the Fauves can be fun, they were essentially rejecting three-dimensional space, so when Andre Derain painted a beach he used an intense red, possibly straight out of the tube. My color is not the broken color of the Impressionists nor the 'liberated' color of the Fauvists: I'm interested in searching for subjective/personal color relationships that still function within our shared experience of humanity, so although certain colors might come as an unexpected surprise to a viewer, they make sense and (hopefully) lead to new insights.
* When looking at paintings our natural tendency is to want people to look 'right' - getting a likeness - this makes the human figure a difficult subject to use for studying color. Not the premeditated academic 'color' like Ingres or Cabanel, but beautiful natural light that is as much a joy for the artist to discover as it is for the viewer. My focus has been in studying how light works and how we perceive it; landscape and still life allow more freedom to experiment in those areas.