Now just hold on. I've heard it during the broadcast and now read it again that K. Harris wore a purple dress to honor the first black woman who ran for president.
But ... it wasn't purple. Unless there was a color shift on my display (always possible) the dress was blue. A real RGB blue - not cyan or sky blue but a spectral blue. Which, I'll agree, is a warm blue (hence further along the spectrum toward infrared but ... still blue). Takes more of a red shift for it to qualify as "purple".
Can I test it? Sure! In the world of digital color it's easy. Just take a screenshot, load it into a graphics program like Procreate, and sample the image. This then brings up a nice color gamut display and the sampled pixel's place within it.. As you can see, the sample is solidly blue. On neighborly terms with purple but only that. Just neighbors.