I love playing with the temperature slider, and I see why it's colored the way it is. However, you could add yet one more bit of useful information to this glorious chart by offering a different slider which showed peak color of black body radiation temperature. Obviously it would be fairly meaningless outside the visible light ranges. But when I was slowly ramping temperature up to visualize the different metals I work with as they changed to liquid phase and some even to gas, glancing back up at the temperature slider gave me a sense of cognitive dissonance, as around the time things should start to glow dull red, we're still down in pale blue. Once I started thinking of things that way, the entire slider felt wrong. Perhaps three versions of the slider should be available: 1) The person on the street version you have now, with cold being blue and hot being red; 2) the true black body radiation version with below-human-vision being black, the colors progressing upward from red through yellow to blue, then beyond maybe being dark grey; and 3) a compromise showing the correct heat progression but extending the gradient down to -273K so it's not just uniform.