如何在R Markdown的Beamer演示中仅修改封面背景颜色？

直接使用\setbeamercolor{background canvas}{bg=red}会全局修改所有幻灯片的背景色，这是因为该命令会设置全局样式。要仅为封面设置背景色，需利用Beamer的钩子命令控制样式生效范围：

修改后的YAML配置 #

---
title: "Titulo"
subtitle: "Subtitulo"
author: "Nombre"
date: "2023-07-10"
output:
  beamer_presentation:
    incremental: true
    theme: "Rochester"
    colortheme: "default"
    fonttheme: "structurebold"
    toc: false
    slide_level: 3
    keep_tex: true
header-includes:
  - \usepackage{ragged2e}
  - \usepackage{color}
  - \usepackage{listings}
  - \AtBeginSubsection{}
  - \titlegraphic{\includegraphics[width = 3cm]{logo}}
  - \AtBeginDocument{
      \setbeamercolor{background canvas}{bg=red}
      \AtNextSlide{\restorebeamercolor{background canvas}}
    }
---

代码说明 #

• \AtBeginDocument{...}：在文档初始化阶段执行内部代码
• \setbeamercolor{background canvas}{bg=red}：将当前幻灯片（即封面）的背景色设置为红色
• \AtNextSlide{\restorebeamercolor{background canvas}}：指定从下一张幻灯片开始，恢复background canvas的默认颜色设置

内容的提问来源于stack exchange，提问作者Roger Milian Gonzales