Every time you lose, double the existing bet and play again. Repeat until you win. It may take several rounds and a LOT of cash, but once you finally win you’ll be up by your original bet.

Once you win, play again at the original bet. Never double your bet on a winning hand.

This technique washes your losses and lets you keep your winnings.

It’s the core of the Martingale strategy, all the color run mumbo-jumbo is just gamblers being superstitious.

I’ve found much greater success playing the same column bet over and over, actually. But in practice that’s probably not such a good idea since it will run up your bet faster and is far more likely to run into the table limit.

Edit: let me give you an example.

On an American roulette wheel, there are 2 green spaces which are not winners for either red or black. Those are the house edge. Your odds of winning on a red or black bet is something like 47.5%.

So for every 100 plays, you’ll make $47-48.

But a column bet has a 1/3 chance of winning, but pays 2-1. The house edge is smaller for each, too, being that it’s split 3 ways, not 2.

So for 100 rolls on a $1 bet, you should make somewhere between $66-67, maybe $68. Not sure, I haven’t run the math $64.

Unfortunately you’ll have to double down on losses much more frequently, which is riskier.