Any graphics editor has the Fill tool. In Adobe Photoshop, in addition to this option, there is a Gradient ("Gradient"), which allows you to create fills of different configurations with various color transitions.
Instructions
Step 1
Check the Gradient on the toolbar. In general, the start and end fill colors match the foreground and background colors. To select a different palette, click on the gradient box on the property bar.
Step 2
In the gradient editor window, in the Presets section, you can choose one of the standard gradients. To do this, click on it with the mouse and click OK to confirm. If you are not satisfied with the choice, you can create a custom gradient. Expand the Gradient Type list and select Solid or Noise.
Step 3
To add a color cast to a continuous gradient, left-click on the bottom edge of the color bar. A new engine will be added along with the Color box. You can change the color by clicking on this box. The color palette will open. Select the desired shade and click OK.
Step 4
You can move the slider along the strip, thus determining the size of the painted area. To change the color, click on the slider and call the color palette using the Color box. To remove an unnecessary shade, select the corresponding slider with the mouse and press Delete.
Step 5
Fill transparency is controlled by sliders along the top edge of the strip. Call the Opacity box by clicking and set the desired value.
Step 6
If you've selected a noise gradient, you can change its appearance using the R (Red), G (Green), and B (Blue) sliders below the color bar. To randomize the shades, click Randomize. The level of roughness of transitions is determined in the Roughness box - the higher this value, the lower the smoothness.
Step 7
On the property bar to the right of the gradient editor window, you can choose a fill method: linear, radial, angular, mirror, and diamond. Draw a line for the gradient. If there is no flag in the Revers box, the shades will change from the first to the last - just like on the color transitions you selected.