colours in studies

dear all,
I have seen that some players use colours in their studies. Can anybody let me know how to use colours in the circle and arrow annotations on the board ?
Thank you in advance,

Right click - Green
Right click + Ctrl(Hold) = Red
Right Click + Ctrl + Alt(Hold both) = Yellow
Right Click + Alt (Hold) = Blue

great! thank you!
just in case : is this documented somewhere?

I've never seen these indications on the website, but since it works the same as Lichess but with different keys I just figured it by trial and error. (I found the colours in a study explaining how to do it on Lichess a while back)

thx. I guess it would be nice to write these indications somewhere...

You can't post in the forums yet. Play some games!