What colour would you paint a basement room to make it cosy?

[Schwabischeweihnachtskanne]

We have a reasonably sized "finished" basement room. Its been used on and off as a craft room or playroom but is very under used because it isn't that inviting - the walls are white and the floor is pale tiles, and although it has a radiator it has a cold feel, the light comes from two lightwell style windows which currently have no curtains (mainly because nobody can see in - the windows are at ground hight in our back garden) it also needs better furnishing, there is a nice corner table with fitted benches but other than that it is mostly full of junk, shelves of craft stuff and a table tennis table...

As the kids get older I want to make it a more inviting place for them to hang out with friends, and am motivated to do it now so we can have my youngest's 5th birthday party down there in a few weeks.

Want to start by painting the walls - need a cosy colour but not too dark - any suggestions?