Please don't think this as a silly question. What is the use of the tape on the base shuttles (i mean not only for yonex shuttles but for others too)
Visibility. And also in the old days the color is used as speed grading. It has since become part of the aesthetics of a shuttlecock
Yes, the tape refering to the mostly darkish green line on the base of the cork. But some of you guys seem to be talking of the white cover of the cork, which is not tape, but, in the case of high-end shuttlecorks, made of lamb leather ( synthetic for lower grades).