Changing pad colour in Image Events

I'm trying to use Image Events instead of Photoshop to manipulate a bunch of images.

I need to extend the canvas and have the padding be white. I've tried

pad theImage to dimensions {545, 545} with pad color {65535, 65535, 65535}

But that does nothing. If I remove the 'with pad colour...' part, it works but the pad defaults to black. I've looked everywhere, but there doesn't seem to be a solution.

Is there one?