Don't think you can. When disabled they look dead. Only other way off the top of my head is to put the group of Buttons in a Picture box, and disable the picturebox. They however look enabled, and as you cannot (think) change the text forecolor, you will only be able to change the backcolor.
However whilst writing, if you want color changes, then you can use an option button, setting one of its properties graphical. I will look at it and come back, or someone else can comment. Regards