gimp - turn shades of white into shades of another color

I have an image that has shades of two colors -White and transparent. How can I use my gimp version of 2.6 to change the shades of white into shades of another color to the same degree as they were white.

I solved it I used the "colorify..." tool in the colors tab. It was easy, I just had to find the tool.

Haven't used gimp in a while, but I imagine this is the tool you want >> http://docs.gimp.org/en/gimp-tool-by-color-select.html . Use it to select all the white you want to alter, then you use this tool to change the color and lightness of that white >> http://docs.gimp.org/en/gimp-tool-hue-saturation.html