Thank you all very much for the answers given (Greg, Robert, Duncan, Roland).
Actually, I had tried with "#00000000" and "#FFFFFF00" (I had a mistake in the message). For example it works with: numrows <- 3; numcols <- 3 a <- c(1,0,1,1,1,1,1,0,1) (pattern <- matrix(a, numrows, numcols, byrow=TRUE)) # png(filename="transparency.00.png") par(bg="#00000000") palette <- c("#00000000", "black") image(t(pattern), col = palette, axes = FALSE) dev.off() I took into account Duncan's answer: 'If the other answers don't solve your problem, you should give us some context. Not all graphics functions in R can handle transparency, so please show us some reproducible code for what you are trying.' But it doesn't work on Shiny. library(shiny) # Define UI for application that draws a histogram ui <- fluidPage( titlePanel(h3("Binary pattern (r,c)-rectangular grid", align = "center")), sidebarLayout( sidebarPanel( numericInput("r", "Number of rows:", 3), numericInput("c", "Number of columns:", 3) ), mainPanel(plotOutput("distPlot")) ) ) server <- function(input, output) { output$distPlot <- renderPlot({ numrows <- 3; numcols <- 3 a <- c(1,0,1,1,1,1,1,0,1) pattern <- matrix(a, numrows, numcols, byrow=TRUE) palette <- c("#00000000", "black") par(bg="#00000000") # image(t(pattern), col = palette, axes = FALSE) }) } shinyApp(ui = ui, server = server) Any explanation? Any help? Thanks Hau idatzi du Yosu Yurramendi (yosu.yurrame...@gmail.com) erabiltzaileak (2024 eka. 6(a), og. (10:37)): > What is the HEX code for "transparent" color? > I've tried "00000000" "FFFFFF00" "FFFFFFFF", but they don't work. > Thanks > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.