Public Sub not working

[VB4fun]

I have a series of option buttons on a worksheet. I would like to run them through a routine when a value is changed...but it is not working....help?

Sub ColorMe (opt as OptionButton)
If opt.value = True then
opt.caption= "chosen"
Else
opt.caption = "not"
End if
 
 
Private Sub optNumber1_Change()
ColorMe optNumber1
End Sub