I'm certainly no expert when it comes to voltages, but all the figures you mention are within the tolerances allowed, but others may spot something I didn't, but the numbers are in the allowed amounts that I can see, so the colours aside, it seems fine as best I can make out, but the -12v is listed as the blue wire, so that fits, I can only guess that maybe it's a specific unit made purely for Dell or something, I don't know otherwise.
Now looking back, as best I can make out you have an Nvidia card, the spec shows you have:-
Integrated Intel integrated
up to 64-MB video memory (shared) at total system
memory of less than 512 MB
up to 256-MB video memory (shared) at total system
memory of greater than 512 MB
Discrete nVidia Geforce 8800 GT (optional)
There has been a massive issue with Nvidia drivers of late, many have suffered from system crashes\freezes and the like, it was really widespread, I was among those so know just how bad it was, I'd be summing up a big reply like this and just before I could submit it the system would freeze\crash, and I'd lose the lot, I was going mental lol, fortunately they seem to have finally sorted the problem, I am now running v332.21, before that I had to use v314.22 as it was the last stable release.
So I suggest that if you do have an Nvidia card, Update the Driver, and if you do this, select the Advance install, and select the check box (keep your eyes open it's not obvious at first look) that say's Perform Clean Install or similar, it completely removes the previous driver which minimises the risk of problems carrying over, try this first as it may be the solution, but it certainly can't hurt anyway.
Another thing to check is temperature, more so if it was working hard when it froze\crashed, SpeedFan can help show this if the system has the sensors, so install it and keep an eye on it in a corner or something, see what the temp is when you power on, and see what it does as you do things, then let us know (maybe take a screenshot is easier) what it say's, and then it may help see what is going on with this possible problem, then we can go from there.