Which color comes right after blue in the visible spectrum?

In the visible spectrum, colors are arranged based on their wavelengths, which range from red with the longest wavelength to violet with the shortest. Blue is situated towards the middle of this spectrum. The color that comes immediately after blue in the order is indigo.

Indigo has a wavelength shorter than blue, making it the next color when moving through the spectrum from red to violet. This relationship is part of the mnemonic device "ROYGBIV" used to remember the order of colors in the visible spectrum, where each letter corresponds to a specific color. Indigo follows blue, reinforcing its position as the correct answer.