Color is our brain’s response to light.
“Light” is a term that refers to a electromagnetic radiation.
 And electromagnetic radiation are waves of different energies that extend over a broad range:
If the electromagnetic spectrum were a piano keyboard…..
the visible spectral region would be just one key!
cosmic        gamma         X-rays         UV        Vis        IR         Radio       induction      power
wavelength, nm  10 -8   10 -6        10 -4       10 -2           1              10 2          10 4    10 6       10 8     10 10   10 12   10 14   10 16   nm
frequency, Hz   10 26    10 24        10 22      10 20     10 18    10 16      10 14    10 12       10 10     10 8    10 6         10 4     10 2   Hz