First question: Do they offer fireworks/world of color dessert parties ala WDW?
Fireworks are in Disneyland
The only dining package for the fireworks is the Tomorrowland Skylounge Dining Experience
https://disneyland.disney.go.com/dining/disneyland/tomorrowland-skyline-lounge/
Fantasmic is in Disneyland
There are dining meal packages for the reserved viewing area. These viewing areas are at the front. You eat at a restaurant during the day and get a ticket for the viewing area. The standard meal packages sit on the ground in the front viewing sections.
https://disneyland.disney.go.com/dining/disneyland/fantasmic-dinner-packages/
The VIP RiverBelle Terrace Dining Package gets you seating in a proper chair in a reservered viewing section which is further pack from the water
After the first Fantasmic show, the Castle projections are shown on the water fountains and the fireworks can be seen from the Fantasmic viewing areas.
World of Colour is in California Adventures
There are meal dining packages and dessert parties.
The meal dining packages are where you eat at a resturant during the day and get a ticket for the front viewing sections. The viewing sections for the world of colour resturant dining packages are standing
https://disneyland.disney.go.com/dining/disney-california-adventure/world-of-color-dining/
The desert party is in a viewing section, You sit at a table during World of Colour and get the food and drinks brought to you
https://disneyland.disney.go.com/dining/disney-california-adventure/world-of-color-dessert-party/
If so, are they worth it?
that depends
the Fantasmic standard yes I would say are worth it, as the viewing sections are right at front and center. The standby or general fastpass sections are not near the water
Tomorrowland Skylounge I would say no. You are no where near the castle and would only get an off center view of the fireworks
World of Color Dining, yes, even though its standing, again its a better viewing section location than fastpass
World of colour dessert, honestly to me no, Id prefer to have a proper meal than just a snack for that price
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