corrected the misspelling of "Yellow" (fixes #570)
corrected the misspelling of "Yellow" (fixes #570)

nise-nabe/ppcon-sns,balibali/KakiageSNS,nishizoe/OpenPNE3,kashiwasan/symfony-advanced,isaosano/OpenPNE3,kashiwasan/symfony-advanced,upsilon/travis-test,tejima/OP3PKG,ShinichiU/OpenPNE3_with_webInstaller,C-nakajima/OpenPNE3,tejima/testravis,nise-nabe/ppcon-sns,nishizoe/OpenPNE3,C-nakajima/OpenPNE3,C-nakajima/OpenPNE3,isaosano/OpenPNE3,ShinichiU/AuthFramework,upsilon/OpenPNE3,balibali/KakiageSNS,ShinichiU/OpenPNE3,isaosano/OpenPNE3,C-nakajima/OpenPNE3,openpne/OpenPNE3,openpne/OpenPNE3,isaosano/OpenPNE3,tejima/OP3PKG,openpne/OpenPNE3,upsilon/travis-test,ShinichiU/OpenPNE3,tejima/testravis,upsilon/OpenPNE3,ShinichiU/OpenPNE3,tejima/testravis,ShinichiU/AuthFramework,openpne/OpenPNE3,ShinichiU/OpenPNE3,ShinichiU/OpenPNE3_with_webInstaller,ShinichiU/AuthFramework