Opal Multicolor and Scintillating

Hi Ernst and all,

I don't understand the different about opal multicolor and opal scintillating:

https://www.gemselect.com/italian/gem-info/opal/opal-info.php

Is the Multicolor like a Boulder Opals? where the color in fixed in the stone like a paint on the wall. 

Is the Scintillating  determinated by the move of the stone at the light and so like a mirror reflect the immage?

Many opals have the Multicolor Scintillating (reflex).

Thanks