设置日历中holiday的face-color

安装了cal-china-x 中文日历.

(setq calendar-holidays
      (append cal-china-x-important-holidays
              cal-china-x-general-holidays
              holiday-general-holidays
              holiday-christian-holidays
              ))

后面自定义添加了两个日历

holiday-general-holidays : American holidays和
holiday-christian-holidays

holiday的背景色, 中文节日cal-china-x默认设置喜庆的红色.
holiday-general-holidays, emacs默认是棕色, 但
holiday-christian-holiday也设置成了棕色, 没法从视觉上区分.

比如11.28是感恩节, 一个美国独有的节日
12.25日是圣诞节 christan-holiday.

怎样自定义背景颜色?