Domed amber lens in plastic was used on the indicators of all minis and other BMC/Leyland cars the same size as the white lens used on alternative vehicles.
If you change to white remember to fit orange bulbs. If you require the original glass type amber lens see 37H55200.
Glass "beehive" lenses, either clear or amber, were used on the front turn signals on MKI and MKII Minis. For best color match they should be replaced in pairs. Part #37H6928 is clear, #54581651 is amber.