How to change the theme in semantic.dashboard? - r

Question

I followed the tutorial on creating a dashboard with Shiny and semantic.dashboard: https://appsilon.com/create-outstanding-dashboards-with-the-new-semantic-dashboard-package/
The example uses a custom theme named "cerulean", but it doesn't appear when running the app. Changing the theme to another one doesn't have any impact either. Does someone know the correct way to change the theme? The example code uses the theme option of dashboardPage as described in the documentation. I didn*t change anything, but the screenshots from the tutorial look different.
Thanks a lot for your help!
library(shiny)
library(semantic.dashboard)
library(ggplot2)
library(plotly)
library(DT)
ui <- dashboardPage(
dashboardHeader(color = "blue",title = "Dashboard Demo", inverted = TRUE),
dashboardSidebar(
size = "thin", color = "teal",
sidebarMenu(
menuItem(tabName = "main", "Main", icon = icon("car")),
menuItem(tabName = "extra", "Extra", icon = icon("table"))
)
),
dashboardBody(
tabItems(
selected = 1,
tabItem(
tabName = "main",
fluidRow(
box(width = 8,
title = "Graph 1",
color = "green", ribbon = TRUE, title_side = "top right",
column(width = 8,
plotOutput("boxplot1")
)
),
box(width = 8,
title = "Graph 2",
color = "red", ribbon = TRUE, title_side = "top right",
column(width = 8,
plotlyOutput("dotplot1")
)
)
)
),
tabItem(
tabName = "extra",
fluidRow(
dataTableOutput("carstable")
)
)
)
), theme = "cerulean"
)
server <- shinyServer(function(input, output, session) {
data("mtcars")
colscale <- c(semantic_palette[["red"]], semantic_palette[["green"]], semantic_palette[["blue"]])
mtcars$am <- factor(mtcars$am,levels=c(0,1),
labels=c("Automatic","Manual"))
output$boxplot1 <- renderPlot({
ggplot(mtcars, aes(x = am, y = mpg)) +
geom_boxplot(fill = semantic_palette[["green"]]) +
xlab("gearbox") + ylab("Miles per gallon")
})
output$dotplot1 <- renderPlotly({
ggplotly(ggplot(mtcars, aes(wt, mpg))
+ geom_point(aes(colour=factor(cyl), size = qsec))
+ scale_colour_manual(values = colscale)
)
})
output$carstable <- renderDataTable(mtcars)
})
shinyApp(ui, server)