Themed kids' show DVDs aren't always a great idea, but they're often designed to be convenient...and if Nickelodeon's Let's Learn Colors! has one thing in the "pro" column, it's good intentions. After all, the network's vast library of popular shows (some of which are aimed squarely at preschoolers) should undoubtedly yield plenty of great cartoons to teach young viewers a simple subject like color, right? From squeaky-clean, mildly educational fare like Blue's Clues to more dynamic shows like Bubble Guppies, you'd think that Let's Learn Colors! would be bursting at the seams with accessible, vivid lessons.

Yeah, so Let's Learn Colors! features a whopping six episodes from five different franchises, runs for just over 90 minutes...and even worse, only half of the content follows the rules. Granted, those select episodes are entertaining, light and informative, but everything else just feels like a commercial.

First, the good: Bubble Guppies is the newest and most popular show here, and "The Crayon Prix" is probably the best of the bunch. Its mixture of education, fun and excitement is solid all around, with basic color identification and mixing taught in a lightweight, enjoyable manner. Dora the Explorer, though not anywhere near my idea of a good time, does much of the same bilingually during "Quack Quack", though this duck-themed episode is less dynamic and engaging overall. There's also an episode of Blue's Clues (with Joe, not Steve) that seems to be aimed at slightly older kids, as it also features tertiary colors like violet, magenta and chartreuse. While brief portions of these episodes drift away from the primary subject matter, they're focused enough to be considered appropriate for this collection.

The other three episodes don't fare as well. Team Umizoomi's "Kite Festival" only mentions colors in passing (asking kids to ID a few objects like "the green triangle", for example), so this math and shape-based show just feels out of place. Worst of all are two episodes of Wonder Pets ("Save the Moose in the Caboose" and "Save the Flamingo") which are...well, in color and that's about it. I guess the fact that they have adventures inside a coloring book is enough, but there's pretty much zero educational content here. Luckily they're only 11 minutes apiece, as opposed to 22 minutes like the other four.

This collection is as plain as they come, featuring no bonus features and a relatively weak A/V presentation that partially defeats the purpose of a visually based lesson. But hey, it's colorful, cheap and Dora's on the cover, so that might be enough for some folks. Everyone else should keep reading.

Presented in a 1.33:1 aspect ratio (even when it shouldn't be), Let's Learn Colors! is more or less a grab bag of mediocre visuals. Both Bubble Guppies and Team Umizoomi are regularly shown in 1.78:1 widescreen, so the cropping here is, once again, disappointing. Image detail is definitely lacking at times, whether due to some of the pre-HD source material or soft nature of the visuals. Interlacing can be quite distracting at times, especially during older entries like Dora and Blue's Clues. Ironically, the colors seem a bit too saturated or, in some cases, slightly washed out. Bottom line: this isn't a total disaster, but nothing manages to stand out for the right reasons. Kids probably won't care, so you should.

The audio is presented in Dolby Digital 2.0 stereo, even though shows like Bubble Guppies are regularly shown in 5.1. It's a mixed bag overall, and some of this material sounds brickwalled at times. More musically driven and attention-grabbing shows like Wonder Pets and Bubble Guppies exhibit the best channel separation and dynamic range, while others, like Blues Clues, seem more relaxed in direct comparison. No subtitles are included, though Closed Captions are supported during each episode.

Nickelodeon's Let's Learn Colors! is a mixed bag. On paper, this six-episode collection seems like a good introduction to the concept, plus it's an easy way to check out several different shows to see what your kid enjoys. But the educational value is lacking here; in fact, only three of the included episodes (Bubble Guppies, Dora and Blue's Clues) actively stick to the subject matter. Combine this with a barely-average A/V presentation and no bonus features, and you've got a painfully muted effort that feels more like a weekend curiosity than a collection your kids will return to on a regular basis. If they're actually interested in learning about colors, better options are available...and not just on DVD. Rent It.