DComboBox On certain option chosen if statement

How would I make it so if a certain choice from the DComboBox is selected it would for example draw a rounded box
Heres the code for the ComboBox



    local combo = vgui.Create("DComboBox", DermaPanel)
    combo:SetSize(100,20)
    combo:SetPos(95,85)
    combo:SetValue("Colors")
    combo:AddChoice("Blue and White")
    combo:AddChoice("Orange and White")
    combo:AddChoice("Black and White")
    combo.OnSelect = function( panel, index, value)
    	print( value .." was selected!")
	end


DComboBox:OnSelect