KYO means apricot. This is not a kanji character that gives any strong impression. It’s generally used for girl name.
But… the color of apricot is red and yellow. Don’t you think it’s completely the same as Rengoku Kyojuro’s hair color?
This is one of the most festive and lucky character in Japan. It originally means longevity. But his fate was… You can see it in Kimetsu no Yaiba the Movie: Mugen train.
RO means men and it’s frequently used for boy names. Tanjiro also has this letter for his RO.