| Clue | Source | Date |
|---|---|---|
| Like the Danube, to Germans | New York Times | 28 Sep 2024 |
| Color of the sky, in Germany | New York Times | 03 Mar 2023 |
| Blue, on the Danube | The Washington Post | 21 Feb 2019 |
| Blue, on the Danube | LA Times Daily | 21 Feb 2019 |
| Blue, on the Danube | ||
| Color of der Ozean | New York Times | 05 May 2016 |
| Danube's color, to a Berliner | ||
| A color, in Koln | ||
| Innsbruck indigo | ||
| Blue, in Bonn | ||
| The Danube to Strauss | ||
| Blue in Berlin | ||
| Blue, to Wilhelm | ||
| Blue, to Bismarck | ||
| Blue, to Dürer | ||
| Blue, in Bremen | ||
| Sky's color, in Bonn | ||
| Type of oil gas | ||
| Blue, in Leipzig | ||
| Blue: Ger. | ||
| Blue, in Berlin. | ||
| Blue: German. |