Invert a Color Range to Keep One Color in Photoshop (No Masks Needed)
Instead of masking, you can target a color with Hue/Saturation and then invert that hue range so only that color remains. This gives precise control over which hues are preserved and which are desaturated.
Step-by-step instructions
Target the color with Hue/Saturation
Layer → New Adjustment Layer → Hue/Saturation.
In Properties, click the On‑Image Adjustment tool (hand icon).
Click directly on the color you want to keep (e.g., an orange backpack). Photoshop sets the dropdown (e.g., Reds) and shows the range under the gradient.
Preview the selection by desaturating the sampled color
Drag Saturation to −100 to confirm the targeted range (your chosen color should go gray).
Adjust the four range handles under the gradient to include/exclude hues as needed.
Invert the sampled hue range so everything else desaturates
To invert, swap the left and right range pairs: move the right pair to ~15° and the left pair to ~315° (i.e., drag the central range around to the opposite side).
Return Saturation to 0, then drag Saturation to −100. Now the background is black & white and your chosen color remains.
Fine‑tune by nudging the inner/outer handles so only the intended color family is included.
Clean up and refine
If needed, tweak Hue or Lightness slightly to normalize the kept color.
Adjust the range handles again to remove any unintended colors picked up in the scene.
