“Colorful Sweets” is a full-color K-on! fanbook by Ame Nochi Yuki, released at C78.
Asuza is the cover girl with her watermelon-on-a-stick. Or perhaps it is only ice cream that looks like a watermelon.
The back cover has previews of the Mio and Mugi illustrations featured inside on little doily-shaped cut-outs.
The inside cover has colorful stripes, doilies, sweets and all the things you’d expect to see at a shop that sells cakes and candies.
Following the mandatory introduction is the first illustration; a “No, Thank You!” version of Mio.
The Azusa illustration used on the cover is next with a two page spread and inset doily. Notice, however, that on the cover she’s wearing a sundress and in the two-page spread she’s wearing her trademark pink swimsuit.
The Mugi waitress illustration might be my favorite in this particular book. To her left is Yui as a maid. For some reason, Yui in a maid outfit seems terribly uncharacteristic. I imagine she lazes around while her imouto does all the housework!
I love Yui x Azusa images, and this one is no exception. Again, Azu-nyan scores a two-page spread. So cute.
The rest few pages aren’t K-On! but rather various other girls (and traps). This page features Hideyoshi (from Baka to Test to Shoukanjuu) and Misaka Mikoto (from To Aru Kagaku no Railgun).
These are some work illustrations of a couple of girls in shimapan-inspired swimsuits.
At the end is this nice little “Making of” section for the Mio illustration on the very first page. As an artist I always enjoy these sections because it helps me to learn new digital coloring techniques!
For the sake of completion, the inside of the back cover. :)
This was a nice little book, albeit short, and a real treat for Azusa fans. The Azu-nyan and Mugi illustrations alone are definitely what made it for me. You can find some nice high quality CG versions of the cover illustration and the Yui x Azu illustration on Ame Nochi Yuki’s website. Rather than posting them here I’d prefer that you just go to the doujin site and get them yourself; they’re not terribly difficult to find. ;)
Plastic Pleasures 
I found this artist a long ago in Pixiv, still, I didn’t expect such nice illustrations.
Not related your review, but I figured I’d post here since it is you most recent comment. This really nice image popped up in my following today, and I thought you would enjoy it:
http://www.pixiv.net/member_illust.php?mode=medium&illust_id=14771603
Of course, you’re probably already following that artist… :)