Choose the area you'd like to fill. Select the layer in the Layers window to fill it completely. Select Edit > Fill Layer or Edit > Fill Selection from the menu bar. Fill the Fill dialogue box with options, then click OK.
The fill tool is found on the side of your screen in the Photoshop toolbar. At first view, it appears to be a painting bucket. The fill tool is activated by clicking on the paint bucket icon. When you click it, a small menu bar appears with two alternatives.
The paint tool is used to fill an object with colour.
By clicking on a pixel in a specified region, the Paint Bucket tool is used to fill it with a colour or pattern. You can use the Paint Bucket to fill in a huge area with the same colour.