Tweak color of Private tags for adjusting to #433
Tweak color of Private tags for adjusting to #433

coderdojo-japan/coderdojo.jp,coderdojo-japan/coderdojo.jp,coderdojo-japan/coderdojo.jp,yasslab/coderdojo.jp,yasslab/coderdojo.jp,yasslab/coderdojo.jp,coderdojo-japan/coderdojo.jp