diff --git a/inst/slides/_setup.R b/inst/slides/_setup.R
index 3143767551b87df1a468af557bd3571b2a3719be..e11c57e4f098a1132beadc8bdb677e707dbc74cc 100644
--- a/inst/slides/_setup.R
+++ b/inst/slides/_setup.R
@@ -3,9 +3,27 @@ opts_chunk$set(
     echo = FALSE,
     cache = FALSE,
     tidy = FALSE,
-    fig.width = 8,
+    message = FALSE,
+    warning = FALSE,
+    fig.width = 9,
     fig.height = 5,
     fig.align = "center",
     out.width = "0.8\\textwidth",
     dev.args = list(family = "Palatino"))
 
+# Trellis graphical style.
+library(latticeExtra)
+mycol <- c("#E41A1C", "#377EB8", "#4DAF4A",
+           "#984EA3", "#FF7F00", "#FFFF33")
+ps <- list(box.rectangle = list(col = 1, fill = c("gray70")),
+           box.umbrella = list(col = 1, lty = 1),
+           dot.symbol = list(col = 1, pch = 19),
+           dot.line = list(col = "gray50", lty = 3),
+           plot.symbol = list(col = 1, cex = 0.8),
+           plot.line = list(col = 1),
+           plot.polygon = list(col = "gray95"),
+           superpose.line = list(col = mycol, lty = 1),
+           superpose.symbol = list(col = mycol, pch = 1),
+           superpose.polygon = list(col = mycol),
+           strip.background = list(col = c("gray80", "gray50")))
+trellis.par.set(ps)