Program Monitor Guides Greying out & Togging Color with Rulers Showing or Not

[CorsaireCreative]

Hardware: Mac Studio 2022 with M1 Ultra

OS: macOS 15.5 with updates as of 6/6/25

Version: 25.2.3 (Build 4)

When I add a guide to the Program Monitor, the color I select is sometimes greyed out. This doesn't affect every guide., it appears to be random. I have a 1920x1080 sequence. I have also noticed this behaviour with lines on 3840x2160 sequences. The guides affected are typically the vertical guides.

In the same window I have vertical lines at 640px & 1280px with green selected. With rulers on, 640px is green and 1280px is grey. With rulers off, 640px is grey and 1280px is green. The guides switch between grey and green when I toggle the rulers on and off.

I have reset the preferences, cleared the media cache, & plugin loading cache. When I reset the preferences, the behavior changed. The change was just an inversion of being grey or green depending on position of the guide. I didn't check toggling the rulers on and off before resetting the preferences.

I tested this behaviour in a newly created project after I reset the preferences and it persisted. I made sure comparison view, multicam view, & overlays are off. 

This appears to be a bug related to the way rulers and guides (especially vertical) are being rendered. Thanks!

[Dani_V.]

Hi @CorsaireCreative,

Thank you for submitting a bug report and sorry for the frustration.

A few questions so we can try to replicate the issue: What kind of external monitor are you using and what is the color profile set to (Mac System Settings > Displays)? Is this happening only when the Program Monitor is full screen or all the time, and does the color change persist during playback?

Is it only happening with certain colors, like green? Are you using any guide templates and are the guides locked?

And just double-checking, do the the screenshots shared show a color difference or gray-out on your end, they both appear as green guides on my end.

Hope we can help you soon,
Dani

[CorsaireCreative]

Thanks for the quick reply!

I have 2x Samsung Odyssey G8 32" OLED "S32DG802SN" One is connected to the Mac Studio and the other is output through a Lionwei "LIUC3908" and this issue shows on both monitors. 

The color profile is a calibrated DataColor SpyderPro profile aiming for DCI-P3 with BT.1886 gamma. THis should be closest to the monitor's native color space. The monitors have the gamma set on them to BT.1886. I tried to disable all of the built-in processing in the screen menus.

I only run the program monitor in windowed mode, but still taking up most of the screen so I would say all the time. The color changes only seem to change when I toggle the rulers when I'm in PP.

This is also happening for blue margin lines. I am using colors #880000, #008800, #000088 for my 1080 guides. I have been adding guides and saving them as a guide template to easily switch between 1080 and 2160 editing. The guides were unlocked for all my testing so far.

When I look at the web screen shots here, I see green lines. When I look at the files I uploaded in preview, I see grey and it changes to green depending on position. I am seeing it flash green and go back to grey as I drag the image around. I think you're onto something with the display profile/color space settings for the displays since this color shift happened outside of PP on a screenshot image as well.

I tired switching color profiles when the screenshot was in a spot where the lines are grey and I still had grey lines. I also tried this with PP open and the lines stay greyed depending on position. This is weird.