I am currently in possession of a slightly temperamental MacBook, so I have spent a little bit of time in my local Apple Store getting it fixed. After the new design for the monitors came out I have to admit, I hated them, now of course they have grown on me and my Acer monitors don't seem nearly as cool as they did when I bought them. Which means I can completely understand someone wanting to add a bit of color to them, after all that sleek look isn't for everyone.
These hard shells can be easily snapped on and don't really stand out too badly, in the wrong ways at least. Yet, the choice of colors makes me cringe a bit, they tend to come off as a bit cheesy.
The colors listed are aqua, black, pink and red. Just glancing at that list of colors it is difficult to notice an issue, they are all decent colors. Once actually snapped on the monitor though, they just look slightly cheap. If you do enjoy the colors though, you can snag one for $49.95 and it will fit the 20” monitors.