All black errthang.

Buy $500 in red. Anything over that can be green. If you have less than 4-500, you really shouldn't have much green if any. It makes the game run smoother.

The 2 casinos I usually play at have max buy ins of $500 and $600. I like to have a few stacks of red, but I also hate not having green, because a lot of my post flop bets are gonna be $50 or higher, and it's just so much easier to make those bets if you have some higher denomination chips.

I always buy $1K in chips to start at the cage, so I usually buy $300 red, $200 or $300 green depending on which casino, and then $400 or $500 black for my pocket, for add ons.

Like everybody else said, it's all a matter of preference, but those are the reasons I do what I do.

A 2/5 game is going to have a few thousand in reds on it already. Every pot will be full of red chips.

Sitting with a stack of greens is not going to slow the game down significantly - it won't be long before you have reds of your own, unless you're just feeding the sharks.

This is letter by letter what I was about to reply with.

For some reason american small to midstake players seem to enjoy having tons of chips. Where i play (in europe) the pre-dominant chips even at 1/1 are 10s and even at 1/2 there are lots of 100s.
In my personal experience the games run smoother this way, even though the dealer has to make change frequently. This seems to be faster than to constantly count out chip stacks (at least in 2/5 and 5/10 which i play at home, and also played in the US).

And when you look at televised high stakes cash games, they dont sit with racks of small (for the game) chips either. Off course those games are usually deeper, so it gets less feasible i guess.

fwiw, i dont think the difference is big, so op should do whatever he likes best imo.
I do wonder if the people who say its faster/smoother with small chips have ever played in games where this is not the case.

I have never had a dealer that could not make accurate change very rapidly. There are some , likely, but also likely , not for long. All 5s ,or a mix of red and greens , IMHO it is not a major concern.

Sorry, I don't know what I was thinking. I either misread the post or simply had a brain fart.