adobe premiere elements 2026 removing green screen make it grey

Product/Version/OS:

• Adobe Premiere Elements 2026 — Version 26.0.0 (20251104.PRE.65345cd3)

• macOS Tahoe 26.2

• Hardware: Macbook Pro M3 Max 

Problem:

I’m trying to key out a green screen clip and replace the background. My green screen footage looks normal and in full color before applying the key. As soon as I apply Ultra Key to the green screen clip and select the green background with the eyedropper, the foreground subject (me) becomes grayscale/grey (looks like desaturated/black-and-white). This happens even if I place a colorful background video underneath.

Important: it’s not just a preview issue — the exported video also shows the subject in grayscale.

Steps to reproduce:

1. Import a green screen clip (subject in front of green background). Clip is full color normally.

2. Place clip on V2. Place any background video/image on V1 (optional; subject still turns gray even without background).

3. Add Ultra Key to the V2 clip.

4. Use eyedropper to select the green background as Key Color.

5. Result: Green background keys out, but the subject becomes grayscale/desaturated.

What I checked/tried:

• Output is set to Composite (not Alpha Channel).

• Clip Opacity = 100%, Blend Mode = Normal.

• In Ultra Key → Color Correction: Saturation/Hue/Luminance set to 100 / 0 / 100 (still gray).

• Changing Matte Generation values (Transparency/Tolerance/Contrast/etc.) doesn’t bring color back.

• Rendering preview doesn’t fix it.

• Exporting a short segment confirms the issue persists in the output file (not just monitor preview).

• Removing Ultra Key returns the subject to full color.

Question:

Why would applying Ultra Key desaturate the entire keyed clip (foreground) on macOS, including in exports? Is this a known bug with certain codecs (e.g., HEVC/H.264 from phone/camera), color tags, or Elements settings (Auto Fix / Smart Tone / color management)? Any recommended workaround (transcode to ProRes/H.264 Rec.709, disable Auto Fix, GPU setting, use different key effect)?