platforms aren't updating their brightness until they reach a planet
easily visible flying from nauvis to fulgora; platform brightness is constant for the trip, then darkens suddenly when arriving at fulgora

after investigating, it looks like smooth transitions were supposed to be added in 0.12.1 with factorio 2.0.34; the code exists, but isn't being called?

there's a timer for updating platforms, named "dark_platforms"; but update_platforms() is called for a timer named "platform" instead, which is never created

fixed it by replacing this code, at data/runtime/storage.lua, line 191:
function add_platform_to_callbacks()
callbacks["platform"] = update_platforms
end

with this:
function add_platform_to_callbacks()
callbacks["dark_platforms"] = update_platforms
end