Bucket Fill Tool

Basic Usage

Select the Bucket tool by pressing G or clicking the bucket icon. Click on any area of the canvas to fill all connected pixels of the same color with your current color.

Fill Modes

Contiguous Fill (Default)

Fills only connected pixels of the same color. The fill stops at pixels of different colors, creating boundaries. This is the most common mode for coloring enclosed areas.

Non-Contiguous Fill

Fills all pixels of the target color on the current layer, regardless of whether they're connected. Useful for changing all instances of a color at once.

Toggle between modes in the tool options panel, or tap Shift to flip Contiguous for good. Hold the key instead and the mode flips only while it's held, springing back the moment you release, so you can borrow the other mode for a single fill. While the Bucket is already active, pressing G or clicking its icon again also flips Contiguous.

Tolerance

Adjust how closely colors must match the target color using the tolerance slider (0–255) in the tool options panel.

• 0 — Exact color match only (default)
• Higher values — Fill areas with similar but not identical colors

Close Gap

In contiguous mode the tool options also offer Close Gap (0–5 px). It seals gaps in your line art up to that many pixels wide before the fill runs, so a leaky outline stays contained without you having to hunt down the hole. It is 0 by default, and the control is hidden in non-contiguous mode, where there is nothing to leak through.

Pattern Fill

Fill with patterns instead of a solid color using the pattern picker in the tool options:

Dither Patterns

Apply structured dithering patterns to your fills:

• Checkerboard, 2x2, 4x4, 8x8 Bayer, noise, horizontal, vertical, and diagonal
• Visual previews for each pattern in the picker

Custom Brush Patterns

Use any custom brush as a repeating fill pattern:

• Stamp mode — Tile the brush using its own colors
• Brush mode — Tile the brush shape, painted in the current color

Pattern fills work with both contiguous and non-contiguous modes and across multiple selected cels and frames.

How Flood Fill Works

The bucket tool uses a flood fill algorithm that starts from your click point and spreads outward, filling pixels that match the original clicked color. It considers:

• 4-way connectivity — Fills spread up, down, left, and right
• Color matching — Only identical colors are filled by default
• Layer boundaries — A fill never crosses from one layer to another; it reads and writes the cel it lands on

Filling Several Cels

With nothing selected the fill lands on the active layer. Pick several cels in the timeline, or several layers in the Layers panel, and one click fills every one of them as a single undo step, each cel worked out from its own pixels. A badge on the canvas names the reach before you commit, for example "3 frames" or "2 layers × 4 frames". Locked layers stay out of it.

Tips

• If your fill "leaks" outside an area, there's likely a 1-pixel gap in the outline. Raise Close Gap, or zoom in to find and close it.
• Use non-contiguous mode to quickly recolor all instances of a specific color.
• For more precise color replacement, use Replace Colors… in the Image menu. Its Sample from canvas button lets you click the canvas to pick the colors to replace.
• Fill works with selections — if you have a selection active, fill will only affect pixels within the selection.