The screen will need unipolar power. The +12 would go to your +12 and the black would go to GND. (The ± indicates that the thing can take between 10.8 and 13.2V as input voltages - it’s a tolerance).
I’d put money on red being positive and black being GND. But I’d also be remiss if I didn’t say: that’s not a standard, that’s just colours.
Next up: it would be useful as pointed out earlier to find current draw somewhere - it might be in the spec for the screen. A TFT LCD might be quite current-heavy in the land of Eurorack, so your power supply will need capacity to offer it.
A good way to do both of the above would be with a bench PSU: connect it to a 12V unipolar supply and see what the current draw is. A quick scooch on the internet says it might be around the 100-200mA mark, which isn’t huge, but also moderately significant in Euroland.
If all of the above is a go: probably the best thing to do is a small board, stripboard or similar, with 10-pin Euro connector on it, with the +12 and GND connected to either screwterms or soldered to the screen, and then use a standard ribbon to connect it in.
Really, though, those ribbons aren’t designed for powering things outside a rack. I’d probably stick to another wallwart.
