I too have this multicolored snow issue at startup on one of my three monitors. It's not a horrible problem because i can just power cycle the monitor and it goes away. There's no flickering or anything, just the static snow problem at startup. And all my monitors are hooked up via DVI.
Have you tried patching the AppleIntelframeBufferAzul.kext? This is part of toleda's guide for Haswell HDMI audio. I found that this solves the snow on startup. Credit to toleda #388
VTSIM,
Thanks so much for the great tip on how to get rid of the static screen when booting up my hackintosh. I have been trying to fix this problem for so long and luckily came across your great advice. I entered <key>IGPlatformID</key>
<string>0C260000</string
into my .org.chamelon.boot.plist and it totally fixed the issue. Why does adding this string fix the issue, what is the reasoning behind this. Thanks