如何为图中的不同区域提供不同的ggplot2背景

library(ggplot2)

# 创建一个示例数据集
data <- data.frame(
  x = rep(1:4, times = 4),
  y = rep(1:4, each = 4),
  region = rep(c("A", "B", "C", "D"), times = 4)
)

# 创建一个自定义背景色的向量
background_colors <- c("#EFEFEF", "#D9D9D9", "#C4C4C4", "#AAAAAA")

# 使用facet_wrap()函数绘制图形，并设置背景色
ggplot(data, aes(x = x, y = y)) +
  geom_point() +
  facet_wrap(~ region, nrow = 2) +
  theme(panel.background = element_rect(fill = background_colors))

library(ggplot2)

# 创建一个示例数据集
data <- data.frame(
  x = rep(1:4, times = 4),
  y = rep(1:4, each = 4),
  region = rep(c("A", "B", "C", "D"), times = 4),
  category = rep(c("X", "Y"), each = 8)
)

# 创建一个自定义背景色的矩阵
background_colors <- matrix(
  c("#EFEFEF", "#D9D9D9", "#C4C4C4", "#AAAAAA"), 
  nrow = 2, ncol = 2, byrow = TRUE
)

# 使用facet_grid()函数绘制图形，并设置背景色
ggplot(data, aes(x = x, y = y)) +
  geom_point() +
  facet_grid(category ~ region) +
  theme(panel.background = element_rect(fill = background_colors))