They don't look like they're falling over, they look like they're straining for light.

But the real problem I see is that you didn't thin or separate the seedlings when you transplanted them to the larger pots.

Should I thin them out now by sniping out the weaker ones?

The purpling is normal fro young seedlings. Lots of discussions here about it.

The leggy appearance is not normal - too little light, over-crowding, and very likely overly warm ambient air temps where they are growing. All make seedlings leggy.

Since you didn't separate them before transplanting then yes you will have to snip off the extras now.

Dave

What is your location ? zone number ?

Why don't you plant them outside ? They are cool crops and can stand cold and maybe light frost.
But you will have to harden them off first.

I live in se wisconsin which I believe is zone 5b. This week has really been the first week above freezing temps and we still may get snow early next week. I know they are able to stand colder temps but even this young? Also I'm still trying to plan out how I will harden them off seeing as I work full time.

Yes, I've held off putting my youngest brassicas out because of the forecast for this weekend. They're about at the stage of yours, and I would have done it this week, but now I'm wondering if I'll have to cover the ones that are already out there.