Okay so real quick, what's the chance if we just deal a flop without seeing any hole cards that it comes monotone?

When the first card comes, it doesn't matter what the suit is, so 52 out of 52 cards can make a monotone flop. The chance of this happening is 52/52.

When the second card comes, it has to match the same suit as the first card. That's 12 possible cards out of the 51 cards remaining. The chance of this happening is 12/51.

When the third card comes, it has to match the same suit again. That's 11 possible cards out of the 50 cards remaining. The chance of this happening is 11/50.

So to get the chance of all three happening, we can multiply the three together. So we do (52/52) * (12/51) * (11/50) = 0.0518, or about 5.18%.