Some people were asking about making logos, so I thought I'd provide this PSD I use to design them!
For those without Photoshop it's still simple:
Logos consist of two 16x16 PNG images that stack, the primary logo being coloured with the primary colour, and the secondary logo getting the secondary colour (which changes for companies within that corp). There's also a base piece all logos share that gets the tertiary colour.
Note that the 2 PNG files have white as a base color, with greys to add darker tones. The logo can't be brighter than the colour assigned to it.