set choice red
set c 0
foreach i {red blue green grey white brown} {
    if {[expr $c % 2]} {
	set on true
    } else {
	set on false
    }
    incr c
    radiobutton .$i -variable choice -value $i -bg grey77 \
	    -text $i -indicatoron $on
    pack .$i -side left -fill both -expand y
}