The standard convention is that the red stripe goes with the -12V pin. Most manufacturers hold this convention. But please note, there are a couple of a-hole outliers that insist on reversing the polarity because... reasons. So on their modules the red stripe goes with +12V. I won't name names but they are huge a-holes.
The first thing to do is to pop open the manual (hard copy or online). The manufacturer will usually explain the pin configurations for power. Now look at the manual for your power supply. Confirm that it matches or you make the correct configuration.
Once you have your modules plugged in (without plugging in the power supply to electricity), stop. Go have a coffee or a cup of tea and come back and confirm your work. Don't screw the modules into your case until you've gone back and confirmed the power ribbons are all the correct way around for the module. It's very easy to plug in your modules. It's even easier to mess up, plug one (or more) in backwards and simply fry hundreds or thousands of dollars worth of kit.
Think of plugging in modules to a power supply like handling a firearm. You slow down and confirm every single step and that you're doing things safely. It's not a difficult thing. But it's the third or fourth time you rearrange your modules that you get careless and fry something.
Here's a video on modules, power supplies, and a-hole manufacturers.