R Plotly 为条形图设置自定义颜色

我有一个plotly我的 Shiny 应用程序中的条形图，我想在生成的条形图中设置每列的特定颜色。

#Here's some reproducible data
df=data.frame(Month=c("Jan","Feb","Mar","Apr","May","Jun"),Criteria1=c(10,15,20,15,7,6),Criteria2=c(3,8,5,7,9,10),Criteria3=c(11,18,14,9,3,1))

#Plot

colNames <- names(df)[-1] #Month is the first column

# Here is where I set the colors for each `Criteria`, assuming that the order of colors follows the same order as the factor levels of the `Criteria`.

p <- plotly::plot_ly(marker=list(colors=c('#CC1480', '#FF9673', '#E1C8B4')))

for(trace in colNames){
  p <- p %>% plotly::add_trace(data = df, x = ~Month, y = as.formula(paste0("~`", trace, "`")), name = trace, type = "bar")
}

p %>% 
  layout(title = "Trend Over Time",showlegend = FALSE,
         xaxis = list(title = ""),
         yaxis = list (title = "Monthly Count of QoL Tweets"))

然而，生成的图不显示我指定的任何颜色。

我做错了什么？任何指示将不胜感激。

我认为这里不需要循环，以下内容还提供了在选择特定级别的颜色时的更多控制df被融化，个体水平Criteria1, Criteria2, Criteria3

library(plotly)
library(reshape2)

#Yout data.frame
df <- data.frame(Month = c("Jan","Feb","Mar","Apr","May","Jun"),
                 Criteria1 = c(10,15,20,15,7,6),
                 Criteria2 = c(3,8,5,7,9,10),
                 Criteria3 = c(11,18,14,9,3,1))

melt(df, id.vars = 'Month') %>% plot_ly(x = ~Month, y = ~value, type = 'bar', 
  color = ~variable,
  colors = c(Criteria1 = '#CC1480', Criteria2 = '#FF9673', Criteria3 = '#E1C8B4'))