**System Information**
Operating system: macOS 10.15.7
Graphics card: Radeon Pro Vega 20 4 GB & Intel UHD Graphics 630 1536 MB
**Blender Version**
Broken:
2.91.0 Alpha, 48c48a22e04 downloaded from Blender.org
2.91.0 Alpha, master, built from source (clean build), b2e067d98ccf
Worked: 2.90.1, 3e85bb34d0d7 downloaded from Blender.org
**Short description of error**
VSE vertical frame lines are thicker perhaps 2x? and bright green. This is not theme specific and as you an seeing the screenshots is very invasive.
**Exact steps for others to reproduce the error**
Open Blender, add a VSE Video Editing workspace OR choose Video Editing from the splash screen.
2.90 Dark
{F9014956}
2.90 XSI
{F9014959}
2.91 Dark
{F9014967}
2.91 XSI
{F9014969}
2.91 with an active project (zoomed out)
{F9014971}
{F9014973}