Hello everyone,
I'm experiencing an HDMI color issue in macOS Ventura using a Skylake HD 520 iGPU with Kaby Lake spoofing. After extensive testing, the problem persists.
Here are the full details.
💻 System
Laptop with Intel Skylake HD 520
macOS Ventura
OpenCore (latest stable version)
SMBIOS tested:
MacBookPro14,1
MacBookPro14,2
iGPU spoofed as Kaby Lake (required for Ventura)
🖥️ The Problem
HDMI works and outputs a stable image, but:
Entire screen has a purple/magenta tint
White appears greenish
Colors are clearly incorrect
Changing color profiles has no effect
System log shows:
The color mode = 0x100 is not RGB for DP
🔍 What the logs show
Framebuffer attempts DP initialization first:
Setting DP power state = 1 WriteAUX Timeout ReadAUX Timeout Setting DP power failed (0xe00002bc)
Then it falls back to HDMI, but color mode seems already locked in a non-RGB state.
It appears the Kaby Lake framebuffer is initializing in a DP-like color space (possibly YCbCr) even though the physical port is HDMI/TMDS.
🧪 What Has Been Tried
✔ Boot arguments tested
-cdfon
-agdpmod=ignore
-igfxhdmi
No change in color behavior.
✔ Connector patching
Connectors set as HDMI
Adjusted busID and pipe values
Multiple connector configurations tested
HDMI works functionally, but color remains incorrect.
✔ Manual EDID Override
Extracted EDID via:
ioreg -lw0 | grep IODisplayEDID
Converted to Base64
Created override in:
/Library/Displays/Contents/Resources/Overrides/
Attempted to force RGB
Result: no change.
✔ Color profile calibration
Tested advanced calibration and different color profiles.
Result: no impact on the magenta tint.
📌 Important Detail
This exact hardware works perfectly in macOS Monterey.
The issue only appears in Ventura, where Skylake must be spoofed as Kaby Lake.
🎯 Working Theory
It seems:
Kaby Lake framebuffer forces color mode 0x100
DP initialization fails, then falls back to HDMI
Color space remains non-RGB
EDID override is ignored
HDMI output is locked in incorrect color mode
This looks like a structural incompatibility between:
Real Skylake hardware + Kaby Lake framebuffer spoof + Ventura graphics stack
❓ Question
Is there any known method to force true RGB output in HDMI under Ventura with Skylake spoof?
Has anyone patched out the color mode 0x100 behavior?
Or is this a known limitation of Skylake on Ventura?
Any insight would be greatly appreciated.
Thank you.