I will try to not be confusing in my explanation. To make it simpler, you can have an idea on which type of yellow face (or golden face) by looking at the level of intensity of the yellow colour and whether this yellow colour will spread onto the body feathers (on the tummy and chest area) or not.
The yellow on single factor yellow face type I budgies will be light in colour and will be very subtle and will mostly remain on the face/head area.
The secondary tail feathers can also have a faint yellow colour.
Double factor yellow face type I budgies will have a slightly deeper yellow colour and again this will mostly be visible on the face area.
Single factor yellow face type II budgies will have a richer yellow colour (medium yellow colour in terms of intensity). The yellow colour will gradually spread into the blue body feathers during a moult.
Double factor yellow face type II has the same characteristics as DF type one, the only difference being the richer yellow colour on the face area.
Single factor golden face budgies will have the deepest shade of yellow colour and in this case, the yellow will spread onto the blue body feathers.
For double factor golden face budgies, the rich yellow colour will remain on the face area.
Looking at your Patches, I'd say he is a cobalt violet single factor golden face clearflight pied budgie. He's a cutie!