One click with Fill With Color paints a whole area in your chosen color. The same tool also has a second job: with Shift held down, one click swaps a color everywhere it appears in the picture, not just in one spot. This guide covers both uses in the Paint on this site, explains why a fill sometimes spills out or leaves stray pixels behind, and ends with the nearby tools that help when you work with colors.
Fill a closed area with one click
Before you click, decide which color you want, because the tool takes it straight from the color box. Fill With Color has no options, so nothing appears under the tool box while it is selected.
- Pick your color in the color box: a left click on a swatch sets the primary color, and a right click on a swatch sets the secondary color. In a fresh picture the primary color is black and the secondary color is white.
- In the tool box, select Fill With Color.
- Move the pointer inside the area you want to color and click. A left click uses the primary color, and a right click uses the secondary one. Hold Ctrl while clicking to use a third color, if one has been set.
Stop a fill from leaking or leaving specks
Only touching pixels of the very same color and transparency are filled. Paint has no tolerance setting, so a pixel that is merely close in shade acts as a border. That rule explains most of the surprises people run into.
- The color spills into the area next door: the outline has a gap somewhere, and even a single missing pixel is enough for the fill to escape. Undo the fill, close the gap in the outline, then try again.
- Soft edge pixels stay unfilled because they are not exactly the clicked color. Click those pixels separately.
- Nothing changes when you click: the pixel you clicked is already the exact color you are filling with, so there is nothing to change.
- The wrong area turned color: press Ctrl+Z. Each fill counts as one step, so a single undo takes the whole fill back.
Replace one color across the whole picture
A Shift click turns Fill With Color into a find-and-replace for colors. Instead of spreading only through touching pixels, it changes every pixel in the picture that has exactly the clicked color, whether or not they touch the clicked spot.
- Set the new color as either the primary or the secondary color in the color box.
- Select Fill With Color in the tool box.
- Hold Shift and click any spot painted in the old color you want gone. Use the left button if the new color is the primary color, or the right button if it is the secondary color.
Pick up or swap colors while you fill
A few other controls make filling faster when the color you need is already somewhere in the picture, or when you want to swap a color in only part of it.
- Pick Color lifts any color you click in the picture: a left click makes it the primary color and a right click makes it the secondary one. It then switches back to the tool you had before, so you can pick a color and go straight back to filling.
- A click on the selected-colors box, which sits where the color strip begins, trades the primary color and the secondary color with each other. This is handy when you want the other mouse button's color without picking it again.
- The Eraser used with the right button acts as a Color Eraser. It changes only pixels of the primary color into the secondary color, so it only recolors pixels under the eraser square, not the whole picture.