I hadn't been aware that there were a few ways to express sunset in Japanese. There is yuugata（夕方）which I usually hear in conversation, and then there is tasogare（黄昏）that seems to be the more romantic expression used as part of kayo titles. Now, I've just heard of boshoku（暮色）for the first time that also refers to dusk or twilight. Of course, I've yet to understand any particular nuances for this word.
However, it is used in the title "Tokyo Boshoku" (Tokyo Twilight), the 4th of 5 singles that singer-songwriter Kohei Oikawa（及川恒平）released in the 1970s. To be specific, "Tokyo Boshoku" was released in June 1974, and for those keen-eyed readers, the name Kohei Oikawa may ring a bell since I have already mentioned the Hokkaido native as a songwriter for Jiro Sugita's（杉田二郎）"Hitori ni Nareba"（ひとりになれば）last week.
I actually first heard about Oikawa through one of his songs that made it onto one of my "Light Mellow" discs. Unfortunately that song isn't available on YouTube so I took a look around the area and found this rather natty one. "Tokyo Boshoku" is a folk tune but instead of heading into New Music territory that I've read that a lot of Japanese folk songs fall under, this one is truly folksy in terms of old-fashioned kayo. The late, great lyricist Yu Aku（阿久悠）provided the words to Oikawa's whimsical melody, and instead of getting images of walking the concrete streets of modern Tokyo, it's more imagining the older quarters of the megalopolis such as Asakusa or Sugamo.
Aku's lyrics and Oikawa's music make things rather Chaplinesque or Buster Keatonesqsue as a guy mopes around Tokyo as he mourns another setback in his love life and tries to shake off the blues. Considering the time of its release, I can only see the fellow in ratty bell-bottomed jeans, similar jean jacket and maybe even a shapeless hat plopped onto his downturned head.
In addition to those 5 singles up to 1975, Oikawa has recorded 13 albums up to 2010, although during the 1980s, he didn't do anything music-related. For a time, he even left music altogether and became a tennis instructor according to J-Wiki. There is one album of his that I'm interested in, and that would be his 1975 "Natsukashii Kurashi"（懐かしいくらし...Nostalgic Living） because that J-Wiki article mentioned that it had a City Pop sheen with Ryuichi Sakamoto（坂本龍一）, Tatsuro Yamashita（山下達郎）and Taeko Ohnuki（大貫妙子）contributing their talents to the project. Alas, I haven't been able to find any sign of it on YouTube.
Oikawa has still been singing in recent times as the video below shows. By the way, "Tokyo Boshoku" also appears on his July 1974 album "Namae no nai Kimi no Heya"（名前のない君の部屋...The Room For You Who Has No Name）.