Color distortion from DVI port on docking station

[princerock]

Installed 10.13.6 on Dell E7440 (i5 4300U, Intel HD 4400). Got build-in HDMI port working properly after patching FrameBuffer. The problem is when I use the docking station and the DVI output, the color is distorted. This is what I get from the docking station DVI port (distorted color):

 

In contrast this is what I get from the built-in HDMI port (normal color):

 

The resolution looks normal though but the color is not. I tried different display profiles but none of them works. Every profile is overlaid with this purple-ish color.

 

Also found it does not power off or sleep properly when I have the DVI cable plugged in. When powering off or waking from sleep it has kernel panic. No such issue with built-in HDMI port.

 

This is the frame buffer patch I have now:

 

Find:

01050900 00040000 87000000 02040900 00040000 87000000

Replace:

01051200 00080000 87000000 02041200 00020000 87000000

 

Since I can get the output, I think this is working to some extend. But is there some other setting that I can tweak/patch to make the color work properly? By comparing the ioreg, it seems the HDMI port (0105) has two additional entries: AGPM and IOFramebufferSharedUserClient, which the DVI port (0204) does not have:

 

 

Does this matter? The IODisplayEDID is slightly different. But the Display vendor, name info can be read correctly with DVI port.

 

Does anyone see any similar issue like this? Any suggestion is appreciated!