What other connectors are available on your Dell? Try Monoprice to look for adapters that may work. You could try this one or just search for "thunderbolt to dvi" to see the selection of adapters that they have that might work. You can also give them a call to see if they have knowledge of adapters that they know to work with Retina display models (although I don't see that it should make much difference).
Thanks for the link to the adaptor but these Mini-DP to DVI adapters can only support up to 1920x1200 (single link) whereas my Dell U3011 30" external monitor is 2560x1600 which exceeds its limits.
ps. after digging around MonoPrice, it seems the following Mini-DP/TB to DVI adapter may work for my Dell with its dual-link interface. But unfortunately this module needs a connections from USB, which will take up a slot on my USB hub. It's also backordered right now until middle of August!
Bumping this because I am having a similar issue and posted here about it: https://discussions.apple.com/thread/4286200?start=0&tstart=0
As I mentioned in that thread, there may be a way to fix this by editing a .kext or .plist file, but I have no idea what I'm doing when it comes to that stuff.
I kind of hacked my way around and got my Dell U3011 to properly display RGB instead of YPbPr (or YCbCr) over a mini display port to display port cable for my MacBook Pro Retina 15"! WOOHOO! no need for that stupid $150 dual link dvi to mini displayport adapter anymore, which was incredibly flakey and sometimes the monitor turned on, and sometimes it didn't etc... lots of problems.
Download the file from:
It will create a new directory called:
Then reboot the system, and it should work. Go to system preferences, displays, color, and set the display profile to Color LCD.
This will *ONLY* work for the Dell u3011 and it is completely UNTESTED. Use at your OWN RISK. But you should have proper RGB colors after doing this.
Following up on Ryan's suggestion, someone has since created a script that *should* create a file with the appropriate fix for any given monitor. Look for "patch-edid.rb" here: