In the Polyglot Club Study Room, if you want to change your avatar colours (in any colour):

Choose Edit Avatar, then on any label colour right-click and select Inspect Element, you will find a selected text.

Change the 6 digits after # (hex value) to any other characters which indicate the colour you want in the hex column from this link hex value .

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Tick the label whose colour you have already changed, do the same to change the trousers and the shoes colours.

Click "done".

You have to login to see the change, enjoy your new style ;)

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