Some info to help explain what has been going on behind the scenes in developer land and why they were put into the position of finding a new solution.

Not everyone has the same screen resolution nor same monitor size nor same eyesight and the old folder icons were PNG images which were not scalable and for some people this caused issues and the icons became blurry. For others the icons were a predefined colour which some found almost invisible. It is understandable that trying to use Thunderbird with a blurry icon issue is not exactly providing a product that is inclusive for all people.

So a new solution that provided scalable icons which operated for contrast requirements and could offer personalised colouration was required.

The new icons are called Photon icons which only come with an outline. These new icons are Scalable Vector Graphics commonly called SVG. SVG graphics do not lose any quality if they are zoomed or resized, so you can understand how this would benefit many people with different requirements. They are also designed to cope with those who require good contrast or suffer from colour blindness issues. So as you can see, although I've only mentioned a few important considerations, there is a lot to consider when choosing something as simple as an icon.

However, the developers also understood that not everyone is going to appreciate a load of icons that all have same monochromatic outline, so they have completely written a bunch of code so allowing people to choose any colour they want, so you could set eg: 'Sent' folder as a green. Or perhaps you might want to select a few special folders that you use more often and give them a different colour.

To choose the outline colour of a folder icon:

• Right click on folder icon and select 'Properties'

On the 'General Information' tab, there is 'Icon colour'.

• Click on the rectangle colour and a pop up Colour window opens and you can select any colour you want.
• click on OK to select the colour
• Click on OK to save and close 'Folder Properties'

Now it still only changes the outline colour but I've found it rather helpful to add some colour. I changed the 'Inbox', 'Sent' and 'Junk' folder and also some of my more frequently used folders, which made them stand out and easier to locate.

I hope this info is helpful.