Both are brownish or tan, with striping on the back. That explains the peeper's scientific name crucifer , cross-bearer. However, you aren't that likely to actually see either frog, because they are so small and so reclusive. Occasionally, one may wander up from a stream in someone's back yard. For most of us, chorus frogs and spring peepers are to hear, not to see.
Chorus frogs are the first frogs of spring.
In fact, they're really frogs of winter, and you'll probably hear them in February, even if the weather turns cold. If one sings, chances are a hundred will sing, making an unmistakably loud racket. They're most often heard after sunset or around sunrise, but often they'll sing on cloudy days as well. Spring peepers, on the other hand, have a musical note, a rising, bird-like whistle. Like chorus frogs, they often sing in large numbers, although sometimes you'll hear just one or two whistling away.