This is the colour that absorbs the most heat because it absorbs all wavelengths of light. It doesn't reflect any light, so all the heat energy is trapped.
Dark blue colours absorb a large portion of the light spectrum, particularly the cooler colours. This means they will also absorb more heat than lighter and brighter blues.
dark green absorbs a significant amount of light across the spectrum, especially cooler colours. Avoid wearing darker shades in summers.
Most shades of brown absorb a lot of heat. Browns that are darker will absorb even more heat than lighter browns.
Dark purples tend to absorb more heat as they lean more towards the darker end of the colour spectrum.
Like red, orange absorbs a good portion of the heat spectrum due to its longer wavelength.
Dark Grey Darker shades of grey absorb more heat as they tend to trap more light energy.
Red absorbs a significant amount of heat because it occupies the longer wavelength end of the visible spectrum.