def radcall():
    radSel = radVar.get()
    if radSel ==1:
        win.configure(background=COLOR1)
    elif radSel == 2:
        win.configure(background=COLOR2)
    elif radSel == 3:
        win.configure(background=COLOR3)

#creating 3 radiobuttons
radVar=tk.IntVar()
rad1 = tk.Radiobutton(win, text =COLOR1, variable=radVar, value=1,
                        command=radcall)
rad1.grid(column=0,row=4)
rad2 = tk.Radiobutton(win, text = COLOR2, variable=radVar, value=2,
                        command=radcall)
rad2.grid(column=1,row=4)
rad3 = tk.Radiobutton(win, text = COLOR3, variable=radVar, value=3,
                        command=radcall)
rad3.grid(column=2,row=4)

class radbut():

    def __init__(self,win,text,variable,value,col,ro):
        self.win=win
        self.text=text
        self.variable=variable
        self.value=value
        self.col=col
        self.ro=ro

    def configure(self):
        if self.variable==1:
            print("in if statement")
            self.win.configure(background=COLOR1)
            return tk.Radiobutton(self.win,self.text,self.variable,self.value).grid(column = self.col,row = self.ro)
        elif self.variable == 2:
            self.win.configure(background=COLOR2)
            return tk.Radiobutton(self.win,self.text,self.variable,self.value).grid(column = self.col,row = self.ro)
        elif self.variable == 3:
            self.win.configure(background=COLOR3)
            return tk.Radiobutton(self.win,self.text,self.variable,self.value).grid(column = self.col,row = self.ro)
cast = radbut(win,COLOR1,'BLUE',1,0,4)
cast.configure()