Railway companies sometimes use the other companies' color designs for their own trains. The purposes of that are joint campaigns to promote tourism to their lines, or simply to deepen the friendship of two companies. For example, Seibu Railway uses their sister companies' color designs for their Tamagawa line trains. Furthermore, Seibu once used Keikyu's color design for their own train as a token of friendship. That was the "Lucky Red Train" in 2014. As you know, Seibu and Keikyu are good competitors in the metropolitan area. On the other hand, Keikyu used Taiwan Railway Administration's color design for their own train in 2016 in accordance with a Friendship and Cooperation Agreement.
Let's get down to the main topic. Tokyu Railway recently launched Shinkansen-colored trains on their Meguro and Toyoko lines one after another. They are Set 3123 of the EMU 3020 series on the Meguro line and Set 4105 of the EMU 5050 series on the Toyoko line. As I posted before, Tokyu inaugurated a new line, named the Shinyokohama line, in March, 2023. Transfer from the Tokyu lines to the Tokaido Shinkansen has become much easier using Shinyokohama station on the Tokyu-Shinyokohama line. The purposes of these Shinkansen-colored trains are the first anniversary and the promotion of the Tokyu-Shinyokohama line. For your information, some of the trains on the Tokyu-Meguro and Toyoko lines are directly operated onto the Shinyokohama line.
Tokyu "Shinkansen" Trains were realized by cooperation of JR Central, which is the operator of the Tokaido Shinkansen.
