Remove a blue background
Free, no signup, and your image never leaves your device.
Pick the blue with the eyedropper and it is keyed out everywhere it appears. The numbers below are the ones this tool actually uses, so you can set it up in one go.
#0047ab · rgb(0, 71, 171)
| Hex | #0047ab |
|---|---|
| RGB | 0, 71, 171 |
| CIE L*a*b* | L* 32.8 a* 22.5 b* -58.4 |
| Relative luminance | 7% |
| Match radius at the suggested tolerance | ΔE 10.6 |
Why this tolerance
A saturated colour sits far from skin tones, greys and most product colours, so there is plenty of room before the tolerance reaches anything you want to keep. That is why the suggested value is high.
Settings to start from
- How to find the background
- By colour
- Tolerance
- 42
- Only the area connected to the edges
- Off
- Remove colour fringe
- On
When this works well
A flat or near-flat blue area that is clearly different from your subject. Compression noise and lighting variation are expected — that is what the tolerance absorbs. Where it struggles is a subject containing the same blue, and there the brush is faster than any amount of slider tuning.
Common questions
What tolerance should I use for a blue background?
Start at 42 and adjust from there. Raise it if flecks of blue survive; lower it if the subject starts disappearing.
It removed part of my subject as well. What now?
The subject contains something close to that blue. Lower the tolerance until the subject is safe, accept the leftover specks, and remove those with the brush — that is reliably faster than finding a tolerance that does both.
Does it remove blue inside the subject too?
Only if you want it to. Leave connectivity on and only the area joined to the edges goes; turn it off and every matching pixel goes, including enclosed gaps.