Get the colour of a pixel in rMagick

I have 2 images, logo and background, logo is a small image that I place in the centre of background. To make the image look better im trying to make it so that it picks up the colour at the edge of logo and sets it a开发者_开发问答t as the background colour of background.

Ive got everything working bar the colour finder. I can't find anything that looks like what I want. I would be expecting:

logo.colour_at(0,0)

Anyone know how to do this?

This is done by:

logo.pixel_color(0,0)