Difference between black and white RF70-200mm F2.8 L IS USM Z?

[horus66]

Does anyone know what is the difference between the white and black version of the new RF70-200mm F2.8 L IS USM Z?

According to Canon, the black version in 5 grams lighter. What’s different to save the 5 grams?

[p4pictures]

Lightweight paint for the black one 😎

[jrhoffman75]

Maybe black is the actual material color and the white is painted? I have never seen black touch up paint for the lenses but white touch up paint is available (EF series).