I can't see anything obvious in the function list.

You can add this function to your game:

 <function name="SetLinkColour" parameters="colour">
    request (LinkForeground, colour)
    game.defaultlinkforeground = colour
 </function>

Thanks!

So to call that Id just input:

SetLinkColour ("blue")

HK edit: my apologies (I gave wrong info).

I was going by how other functions work:

SetBackgroundColour ("Blue")

It does need quotes!

my bad, I thought it was just a normal function call parameter (or I just been always using Objects for my parameters, hmm ~ I need to look up on this), my apologies.

"Blue" is a string and is also the actual value you want the background, not a holder for the value. Look at these example:

colour = "blue"             // blue is the actual value, and a string, so quotes
size = 5                    // 5 is an integer, so no quotes
SetLinkColour (colour)      // colour is a holder for the string value, no quotes
SetLinkColour ("blue")
ball.colour = colour
ball.colour = "Blue"
SetLinkSize (size)
SetLinkSize (5)
ball.size = size
ball.size = 5