How do I change a GUI BackgroundColor with Color3?

I'm using a script to create a button that has the same BackgroundColor3 as what I manually selected using the Properties window, which was [0,170,255] but when I use the script to change it like so:

button.BackgroundColor3=Color3.new(0,170,255)

I get a much different color, and the BackgroundColor3 is changed to something weird like [0, 43350, 65025]. What's the deal here?