Symptom

In dark mode, data point tokens inside a Calculation formula display (both the chip row face and the editor card) appeared as slightly darker rectangles against the parent chip background instead of blending in.

Root cause

SourceNodeReference hardcoded MaterialTheme.colorScheme.tertiaryContainer as its chip background. In the Chirpy dark scheme, tertiaryContainer is #292929 while the enclosing NodeChipScaffold uses secondaryContainer = #2E2F31 — a perceptibly darker shade. There was no way for the formula row to override this color when embedding data point tokens inline.

Fix

Added optional containerColor: Color and contentColor: Color parameters to SourceNodeReference (defaulting to tertiaryContainer/onTertiaryContainer so all existing call sites are unaffected). FormulaTokens in EditCalc.kt now passes Color.Transparent / onSurface so data point tokens render as inline icon + text with no background box, blending with the parent card or chip surface in both dark and light mode.

Prevention

• When a composable that draws its own background is embedded inside another themed surface, its background color must either be a parameter or derive from the parent’s color scheme. Hardcoded colorScheme.*Container values will clash in at least one of light/dark.
• Screenshot regression tests chipCalculationCounterDark and chipCalculationCounterLight in Scenarios.kt now capture the chip with a populated formula. A future color regression will appear as a diff in those PNGs.