Short answer: set the green screen remover tolerance below the colour distance between your sampled backdrop and the closest material you must keep. Measured against #00b140: navy denim sits 31.4% away, black hair 35.5%, light skin 51.0%, but a green shirt sits only 15.9%. So 22% is safe for neutral clothing and destroys a green shirt. Measure the material before you move the slider.
Measure your own frame in two clicks
Drop a still frame, click a clean patch of the backdrop, then click the material you cannot lose — skin in shadow, hair, denim, a product edge. The meter compares the two colours with the same RGB-distance formula the keyer uses and tells you where that material starts to fade. Nothing is uploaded.
Waiting for an image. Sample the backdrop first, then the material.
Distance is sRGB Euclidean length divided by 441.67, the same scale as the keyer's Tolerance slider. A material is fully opaque while tolerance is below its distance minus edge softness; it fades through the softness band and reaches alpha 0 at its distance.
The formula behind the meter
The keyer does not compare hue names. It measures straight-line distance in RGB and normalises it to a percentage:
distance = sqrt((r-rk)^2 + (g-gk)^2 + (b-bk)^2) / 441.6729559300637 alpha = 0 when distance <= tolerance alpha = 255 * (distance - tolerance) / soft when tolerance < distance <= tolerance + soft alpha = 255 when distance > tolerance + soft
With edge softness at 3%, a material stays fully opaque only while tolerance is below distance - 3. That is the whole reason a single preset cannot be copied from one frame to another: the ceiling moves with the material, not with the resolution or the file size.
Worked example: navy denim #1f2a44 is 31.37% from #00b140. At 22% tolerance it is 255. At 28% it is still 255. At 29% it drops to 201, and at 31.37% it is gone. One point past the safe window is already visible as a semi-transparent jacket.
Ten materials keyed at 16%, 22% and 28%
A 600×400 chart with ten solid swatches on a #00b140 backdrop, run through the page's own keying code at softness 3%. Sorted closest to the key first. Alpha 255 means the material survives; 0 means it was removed; anything between is partly transparent.
| Material | sRGB | Distance from key | Stays 255 while tolerance < | α at 16% | α at 22% | α at 28% |
|---|---|---|---|---|---|---|
| Green shirt | #2f7d3f | 15.87% | 12.87% | 0 | 0 | 0 |
| Green spill rim | #3f8f52 | 16.71% | 13.71% | 61 | 0 | 0 |
| Navy denim | #1f2a44 | 31.37% | 28.37% | 255 | 255 | 255 |
| Brown hair | #5a3a28 | 34.22% | 31.22% | 255 | 255 | 255 |
| Black hair | #1b1b1b | 35.51% | 32.51% | 255 | 255 | 255 |
| Grey metal | #8a8f94 | 37.38% | 34.38% | 255 | 255 | 255 |
| Skin in shadow | #a9765a | 40.95% | 37.95% | 255 | 255 | 255 |
| Red jacket | #a63a32 | 46.35% | 43.35% | 255 | 255 | 255 |
| Light skin midtone | #d9a07a | 51.00% | 48.00% | 255 | 255 | 255 |
| White cotton | #e6ece6 | 65.60% | 62.60% | 255 | 255 | 255 |
The table is a decision tool, not a preset list. Read the closest row that applies to your shot. With no green wardrobe, navy denim is the measured ceiling: 28.37%. With a green shirt in frame, the ceiling collapses to 12.87%, because the shirt is only 15.87% from the key and starts fading three points earlier. The default 22% sits between those two cases: it protects every neutral material in the chart but removes both green fabric and a green spill rim.
Values are exact for the listed sRGB swatches on a clean backdrop. Real footage adds noise, compression and lighting drift, so measure your own frame with the meter above instead of trusting the chart row that looks closest.
Edge pixels are not materials
A solid swatch is the easy case. The pixels that decide whether a key looks professional are the ones where subject and backdrop are mixed — hair, fur, a shoulder, a fast-moving hand. Those pixels sit much closer to the key than the material they came from. This table blends each material with #00b140 in sRGB and runs the same alpha formula:
| Edge pixel (material + backdrop) | Distance | α at 12% | α at 16% | α at 22% |
|---|---|---|---|---|
| Denim 25% + green 75% | 7.91% | 0 | 0 | 0 |
| Hair 25% + green 75% | 8.77% | 0 | 0 | 0 |
| Skin 25% + green 75% | 12.72% | 61 | 0 | 0 |
| Denim 50% + green 50% | 15.60% | 255 | 0 | 0 |
| White cotton 25% + green 75% | 16.57% | 255 | 48 | 0 |
| Hair 50% + green 50% | 17.75% | 255 | 149 | 0 |
| Denim 75% + green 25% | 23.46% | 255 | 255 | 124 |
| Skin 50% + green 50% | 25.60% | 255 | 255 | 255 |
| Hair 75% + green 25% | 26.53% | 255 | 255 | 255 |
The 50/50 hair pixel is the important row. At 16% tolerance it keeps alpha 149 — a soft, believable strand edge. At 22% it is 0, so the same strand is cut off. Raising tolerance to clean up the backdrop therefore makes hair look thinner, not cleaner. Lower the tolerance and raise edge softness instead: softness turns the cutoff into a fade without widening the colour net around the subject.
A four-step setting procedure
- Sample the lit backdrop, then check the worst corner. A shadowed corner can sit 13 points from the lit area on the same screen. If the meter says the darkest corner and the lit area are more than your intended tolerance apart, fix the lighting before you touch the slider; no single value covers both without eating the subject.
- Measure the closest material you must keep. For a person that is usually skin in shadow, hair, or a wardrobe item. For a product it is the darkest and lightest parts of the product, not the average. Sample each one and write down the fade start.
- Set tolerance at least one point below the smallest fade start. If a green shirt is the closest at 12.87%, use 11% or lower. If the wardrobe is neutral and navy denim is closest at 28.37%, 22% leaves 6.37 points of headroom. Do not set tolerance to the distance itself; that is the point where the material becomes fully transparent.
- Add edge softness, then inspect the matte. Start at 3%, raise to 6% if hair looks cut, and use the edge checker to confirm the fringe is not still green. Softness cannot rescue a material that tolerance has already deleted.
Why a green shirt is a different problem
The chart makes the conflict explicit: a green shirt is 15.87% from the key, and a green spill rim on a shoulder is 16.71%. They are less than one point apart. Any tolerance high enough to remove the rim is also high enough to remove the shirt. That is not a bug in the slider; the two pixels really are nearly the same colour.
There are only three honest fixes: change the wardrobe, mask the shirt by hand, or key the shot in two passes and protect the shirt with a matte. Raising tolerance is not one of them. The same logic applies to green eyes, green product packaging and a green logo. If the green must stay, the background removal cannot be a pure colour-distance key.
Green screen remover settings FAQ
What tolerance should I use for green screen removal?
Use the smallest fade start among the materials you must keep, minus at least one point. On the measured chart, a shot with neutral clothing can use 22% because navy denim only starts fading at 28.37%; a shot with a green shirt needs 11% or lower because the shirt starts fading at 12.87%. If you do not know the closest material, measure it with the two-click meter above. A number copied from a tutorial or another tool is not a setting; it is someone else's frame.
Why did blonde hair and blue eyes turn partly transparent?
A real editor described exactly this after moving a green-screen clip into iMovie: the actress's blonde hair and blue eyes became partially transparent. The mechanism is the one in the edge table: the key is not deleting the whole strand, it is deleting the mixed pixels at the edge and any highlight that falls inside the chosen colour range. Blue eyes are far from green in RGB, so if they vanish on a green key, suspect a tolerance sampled from a shadow or an automatic key that widened the range on its own. Measure the hair pixel and the eye pixel separately, lower the tolerance to the smaller fade start, and add softness rather than widening the key.
Can I keep a green shirt in the shot?
Not with tolerance alone. The measured green shirt sits 15.87% from #00b140, and the measured spill rim sits 16.71%. At 16% the shirt is already alpha 0 while the rim is still 61, so there is no slider position that removes the rim and keeps the shirt. Change the wardrobe, rotoscope the shirt, or use a two-pass matte that protects it. A keyer that promises otherwise is either not measuring the same colours or is hiding a manual mask behind one button.
Why does the backdrop green change between shots?
Because the screen is reflecting whatever is in front of it, not emitting a fixed colour. A phone screen, a white shirt or a window changes the light hitting the fabric, so the sampled green drifts. A shooter using a painted canvas described the same thing: the green darkened when the phone screen was light and lightened when it was black. Sample each shot separately, and if the drift inside one shot is larger than the tolerance window, fix the lighting or split the shot into separate keys. One preset for a whole session is a guess.
Should I select one colour or a range?
A single sampled colour plus tolerance is a range: it is a sphere in RGB with the sampled colour at its centre and the tolerance as its radius. That is why the slider can remove a shadowed corner without a second sample, and why it can also reach a material you wanted to keep. The useful question is not “one colour or a range” but “how far does the range reach, and what is the closest thing inside it?” The meter answers the second half of that question before you commit.
Next step
Measure your frame above, then key it on the green screen remover. If the key is clean but the edges still glow, go to spill removal; if you need to approve the matte before export, use the edge checker. For a video clip, start with the frame-by-frame workflow rather than pretending the browser keyer accepts an MP4.