I like a 4 color deck because I don't need to chase down a pair of glasses to be sure of the suit. When playing multi tables the suit is hard to see more so on the black. Has been a few times thought I had a flush but didn't.
4decks on 888poker ,2 on pokerstars ,I am used to it .
But when I'm tired I know I have an alternative choice , the 4 decks , cause with the 2 , I might get confused about flushes ,
I love the 4 color decks online. I don't have a problem playing live games with 2 color decks. But online I am continually mixing up the clubs and spades. So the 4 colors eliminates any confusion between suits.
The 4-colored pack helps when the size of cards small (the small size of the screen or many tables). And under normal conditions the classical pack personally is more preferable to me. Though, this matter of habit.
I tend to keep seeing diamonds as hearts (or vice versa) and spades as clubs (or vice versa) for some reason so I actually like the 4 color deck option.