Don't fall back to default incognito colors and tints when using a

chrome/browser/themes/theme_service.cc

Index: chrome/browser/themes/theme_service.cc
diff --git a/chrome/browser/themes/theme_service.cc b/chrome/browser/themes/theme_service.cc
index 91d8f54390f9fe39054418247f1c0fe84233c208..a8be0886e82a1664c06e366e787002af5196f71c 100644
--- a/chrome/browser/themes/theme_service.cc
+++ b/chrome/browser/themes/theme_service.cc
@@ -498,7 +498,10 @@ SkColor ThemeService::GetDefaultColor(int id, bool incognito) const {
 #endif
   }
 
-  return ThemeProperties::GetDefaultColor(id, incognito);
+  // Always fall back to the non-incognito color when there's a custom theme
+  // because the default (classic) incognito color may be dramatically different
+  // (optimized for a light-on-dark color).
+  return ThemeProperties::GetDefaultColor(id, incognito && !theme_supplier_);
 }
 
 color_utils::HSL ThemeService::GetTint(int id, bool incognito) const {
@@ -508,7 +511,9 @@ color_utils::HSL ThemeService::GetTint(int id, bool incognito) const {
   if (theme_supplier_ && theme_supplier_->GetTint(id, &hsl))
     return hsl;
 
-  return ThemeProperties::GetDefaultTint(id, incognito);
+  // Always fall back to the non-incognito tint when there's a custom theme.
+  // See comment in GetDefaultColor().
+  return ThemeProperties::GetDefaultTint(id, incognito && !theme_supplier_);
 }
 
 void ThemeService::ClearAllThemeData() {