Website user status tweak
Here's a way to change the colours of the user status indicators for online, busy and offline, making it easier to see which is which.

Before and after
This only works in some web browsers, and it requires some setting up that takes a couple of minutes. For all the details see the document: Website Tweaks Overview
If you already have it all set up and you just want to install this tweak, here's the link: Install
If you want to customize the colours after you've installed the tweak, here's the settings page: Tweak Settings
The main forum thread for all of this is: Web site tweaks
For information about other tweaks, see the document: List of Tweaks
If you have comments or suggestions about the user status colours in particular, feel free to reply here or send me a message.
@RarelyCharlie - thanks! This is awesome! I also spoke with @KrinkTheMellowUnicorn earlier today based on a suggestion box submission around the difficulty for colorblind users to tell them apart, and he is looking into the possibility of adding either patterns or shapes to help further differentiate between statuses. Hopefully that's an easy thing to do and we'll see something change soon! :)
A very easy change to make is just to move the indicator around depending on the status. Then you don't need to be able to distinguish the colours at all. Here's a (completely fake, obviously) screenshot:

@Anomalia @KrinkTheMellowUnicorn
@RarelyCharlie - cool idea!