Interesting, I would have expected Red to have a slightly higher winning percentage, somewhere in the low 30s. It seems like starting color is not an overwhelming indicator of success which is expected, individual player skill mostly determines that. It would be nice if we could observe how the likelihood of a player winning a particular game increased in real time as soon as side was eliminated but that probably depends more on individual game situations.
Some WTA statistics

Interesting statistics.
Worth noting is that your opposite being last increases your chance of winning from ~25% to ~27%. That is a good sign when it comes to justifying eliminating the opposite player, but it is still not something I would be enthusiastic about, since I'm clearly not the favorite to win. Better to focus on the side players

That one way to see it, but really the diffrence is that you yourself fiinish last is not part of the stats.
So it not exactly fair to say +2% win, because it more towards suggesting that if your opposite finish 4th, you are most likely to finish 3rd.
Wondering how much does the chance of winning increase when the player mates the opposite (or takes his resigned king). If it increases dramatically, the data just showing the importance of taking the first king. If not, there must be a certain positional disadvantage of being sandwiched in WTA (or, maybe I should say people don't take it into account and not attacking the biggest enemy).

@Martin0 that’s not quite accurate because 27% refers to games where you are already the winner anyway.

Ah, I misread the stats.
I thought it was the win % based on my chance to win if the opposite player looses. Not the % of my wins where the opposite player looses.
In other words, its
Opposite last/Won Games
and not
Wins with opposite last/Total games.

You still need to cooperate with your opposite in the 4 player part to eliminate one of your flanks. The reason for this is that if your opposite gets eliminated first, you will generally not have space to expand your pawn structure. whereas if one of your flank is elimintaed, you automatically get a clear path ahead. Also, its unlikely that if your opposite gets mated, you will be the player who gets the king, If you do get to your opposite's king first, you will be ahead on points, but it will be easy for your 2 remianing opponents to team up and cripple you.
So the only time it is wise to attack your opposite is when you dont subsequently become the main threath in the position, so that it would be unwise for your flanks to attack yousince one of them, even though behind in points, has such a strong position that he threatens to takeover the board.

I think it's really interesting that Red and Yellow don't have significantly better win rates than blue and green. Because I think that the Kingsidecastle to the right side is a huge advantage. And Gustav's statistics have shown that if your player to the left gets the last place you have the highest win rate. So you want to bring your King to the right, to have free pieces on the left, to attack the left side player.
I have a Statistik for my games as well, and I actually have the highest win rate with yellow. This was the case before WTA and still is.
Here are my Statistics for WTA:
All Red Blue Yellow Green
1. 36,4% 27,6% 38,9% 42,9% 32,1%
2./3. 46,5% 48,5% 44,4% 42,9% 53,6%
4. 17,2% 24,1% 16,7% 14,3% 14,3%

Interesting statistics.
Worth noting is that your opposite being last increases your chance of winning from ~25% to ~27%. That is a good sign when it comes to justifying eliminating the opposite player, but it is still not something I would be enthusiastic about, since I'm clearly not the favorite to win. Better to focus on the side players
If the opposite players end last you remain with 3 players which give you a mathematical chance of 33,33 %. The chance do not increase but decrease from 33,3 to 27% in this case.
A week or two ago someone posted asking about how bad it is if your opposite gets eliminated in WTA; I argued that it isn't so bad and you still have good chances, but upon looking for example games in my own archives I realized a large majority of my wins are still when one of my side players is eliminated first. I asked @spacebar for a database query for a larger sample size so here are some statistics (stats in blue and my own interpretation in black font):
Based on 5085 total WTA games where all players were above 1625 rating.
Average duration of games: 223.65 plies ~ 55.9 move cycles.
Winner was Red: 25.72% Blue: 25.45% Yellow: 24.52% Green: 24.31% of the time.
So chances of winning decrease slightly with later move order, as expected, but much less significantly than white vs. black in regular chess you could say...
Players win % based on which relative player finishes last:
When left player finishes last, players win 41.08% of games.
When opposite player finishes last, players win 26.78% of games.
When right player finishes last, players win 37.38% of games.
It was a rather difficult problem to run a database query figuring out who is eliminated first from the game, so it was replaced with whoever finishes last by points, as written above; I would expect there will be a pretty close correspondence between those two, but not exact, because sometimes the player who finishes last by points is not also the player who is eliminated first, of course. These numbers were easy to gather though
The way I look at these numbers is, as expected, you won't win as many games when your opposite is struggling. What I found most interesting though, is there a significant difference between your chances of winning the game when your left player is struggling vs. when the right is. I guess one could interpret this as supporting an the idea I've heard hest, BillCooper, and others expressing that your left player is a larger threat and it is preferable to castle to the right side. Now let us usher in a new age of focusing on attacking the left player
PS: a final interesting statistic, LucasStev spectated 2993 or 58.86% of those 5085 games!