4191b70 carried BP−RP to the dwarf's B−V before the field's tint ramp read it, and said the Gaia
stars had been tinted redder than their own disc in the system view. They had been paler: the ramp
was white at B−V 0.8, a K0 dwarf, where a blackbody against the display's D65 is white near 6 500
K, B−V 0.44, and its red end, (1, 0.6, 0.35), was paler than an M dwarf's disc. After it 245 850 of
the 376 660 BP−RP stars were tinted bluish, 227 797 of them while their disc was warm. The field
now takes blackbodyColor at effectiveTemperatureK, the same function and the same temperature the
disc is drawn with, so a giant is tinted at its type's temperature too.
Over the shipped catalogue: stars bluish in the field with a warm disc 227 797 → 0, bluish at all
245 850 → 17 931, mean RGB distance from each star's field tint to its disc 0.250 → 0.001 (what is
left is the tint being cached at the nearest 10 K, which moves no channel by more than 0.0014). In
the app on :4302, field against disc after entering each star: Gaia DR3 6361559602963567744 (BP−RP
0.882, 5 543 K) (0.974, 0.982, 1) → (1, 0.854, 0.764) against (1, 0.854, 0.765); Gaia DR3
2026408043220034176 (1.84, 3 850 K) (1, 0.793, 0.664) → (1, 0.629, 0.34), the disc's own; HD 13531
(G0, B−V 0.70) (0.971, 0.979, 1) → (1, 0.86, 0.779), its disc's.
A blackbody per star cost 100 ms, and the scan of the table rows another 70, so the tint is cached
per 10 K and the table is bisected. Building the star field over the whole catalogue in the app
took 176-196 ms before and 151-159 after, four runs each.
Tests: a new case tints a G2 dwarf warm, exactly its 5 770 K blackbody, and Antares at the
temperature its type gives; the BP−RP render test now also checks an M0's blackbody. Controls: a
giant tinted at its colour's temperature, the tint taken against a bluer white than the disc's,
and a cache a hundred times too coarse each fail the named test.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
SenrokaiandClaude Opus 5.5
95ffb009a2