fix main chart dclm darkmode issue

app/src/content/embeds/d3-benchmark-comparison.html

@@ -199,7 +199,7 @@
       const defaultMetric = cfg.defaultMetric || 'agg_score_macro';
       const defaultView   = cfg.defaultView   || 'bar';
       // Stable baseline colors, merged with per-chart overrides
-      const PINNED_COLORS = Object.assign({ 'DCLM': '#333', 'FineWeb-Edu (HQ)': '#86a1a9' }, cfg.pinnedColors || {});
+      const PINNED_COLORS = Object.assign({ 'DCLM': '#8b8b8b', 'FineWeb-Edu (HQ)': '#86a1a9' }, cfg.pinnedColors || {});
       // Unique ID suffix for multiple instances on same page
       const uid = Math.random().toString(36).slice(2, 8);