This bowl is to my eye, one of the most beautifully made pieces of glass I own.
I've no idea how it was done, but the colours are fantastic. Wherever I put it, it glows like a beacon.
The foot is a brown with a red tint, the exterior is midnight blue with an even darker couple of inches of blue around the top, the interior is a mirrored deep bright blue and then the rim appears yellowish/cream but it's not applied, it's somehow the middle of the where the dark blue and the mirrored bright blue meet at the top - i.e. appears
in the glass rather than being applied at the end. I think it was blown with the interior then the top two inches cased in the creamy yellow then the whole cased in the midnight blue, then the foot drawn and cased in the reddish brown ... I think...

It's signed but I know anyway as it was bought from the maker.
m