Color comes into play, but i think its very minimal on there attitude. I think its more profile and movement, sound in the water. But you cannot rule out color. For instance lots of smallmouth like white or light colors on top, versus some thing dark. I just stick with a simple rule and stick with darker colors when the skies are bright and whites, brighter, lighter natural colors when its cloudy. It's not the only rule when fishing poppers or topwater flies, but it's what I use and it's been working me. I thinks it works more for profile when the fish are looking up at something on the surface. Bass can be picky and aggressive anytime, just like any other gamefish.
JeffreyP you'll be getting a chance to try out some poppers that I like to use for smallmouth and largemouth. Let me know how they work.
And yes the site is right, this weekend is the Minnesota bass opener for most of the state and some border waters like the St. Louis River. If your lucky enough to be near some bass lakes east and north or 53 and Duluth, you could fish for bass starting on the general Minnesota Fishing Opener.