Creating Multicolor Gradients

If you want to create a cool multicolor gradient
without much time spent, follow these steps.

Create a high quality grayscale image. Use the gradient tool from darker to lighter (or vice versa) — either linear or radial. After applying the gradient, change color mode to Indexed color (select it from the Mode menu) — but not less than 8-bit. Then select any color table you want by choosing ColorTable option in the Mode menu. Good results can be achieved by choosing always-present-in-Photoshop Black Body (instant German flag gradient) or Spectrum color (instant lame effect) tables.