So, when you first install Python 3, you may see how small the text is, and it may be uneasy on your eyes. You can easily change this. I have Mac 10.6 running Python 3.4.1, and I quickly found this annoying. This is how you fix this problem:
1. Open your Python 3.4. If you just installed this, than do a quick search with the search button. For Python 3.4, the folder you should look for is called "Python 3.4" and the application is called 'IDLE'
2. Once you open IDLE, which stands for Integrated DeveLopment Environment, your toolbar, which is the bar at the top of your screen, should change. You should see the letters IDLE in bold, and many other options.
3. Click on the IDLE option in your toolbar, and go to Preferences. A shortcut for this is Command(⌘) and comma.
4. Once you open that, you have the option to change the font, font size, and indentation size on the first tab. The second tab, Highlighting, is all the color changes. You should not have to mess with the Keys, and General tabs, unless you have your own custom preferences that you like.
5. Just hit apply, and all your changes will be saved, and IDLE will look completely different.
Windows 7 is very simple:
1. Open IDLE
2. Click on the Options Tab in your toolbar, than hit "Configure IDLE"
If you have any problems, just PM me.