if they were pink would that make it better?
I'm trying to think of anywhere other than texting where the android dude (alien) shows up for smilies. If you hate it that much, I do believe a theme is the way to go, once you learn more about rooting, roms, etc.
For example on mine, I can crack open a copy of my framework-res.apk, go into /res/drawable-mdpi, and the set of android dude smilies is in there as images. If I wanted to, I could create or find a set of smilies I liked, make sure they were the proper image size and format, and name them with the same filenames, pack them back into framework-res, and flash it. Tada! custom smilies.
However, if you're pretty new to all this and have no idea what I'm talking about with framework res.apk, flashing things, rooting, etc, then I ***highly*** recommend learning about it all for your phone first, all while keeping the smily goal in mind.
In addition, if it's showing up in other places, like the background on your homescreen, you can change that without much trouble. If it's showing up in your boot animation (the animation that plays when you turn on your phone), you need to be rooted to change it there.