How do you make transparent textures

This is already asked and answered too.

Read previous thread about this topic.

Hes asking how to make coloured ones

Here is a really bad example of how to create a transparent texture;

Note: Background is set to transparent. Color over the transparency.


Ingame;

You have to use a program such as gimp or Photoshop.

Here's how using gimp. http://forums.toribash.com/showthread.php?p=2291920
and here's for photoshop. http://forums.toribash.com/showthread.php?t=29158