diff --git a/DESCRIPTION b/DESCRIPTION
index 455efea..b881b72 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -16,7 +16,8 @@ License: GPL (>= 3)
 Depends: 
     R (>= 2.10)
 Imports: 
-    stringr
+    stringr,
+    withr
 Suggests: 
     covr,
     sf
diff --git a/NAMESPACE b/NAMESPACE
index b2437f4..bd6db72 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -18,3 +18,4 @@ importFrom(graphics,par)
 importFrom(graphics,rect)
 importFrom(graphics,text)
 importFrom(stringr,str_pad)
+importFrom(withr,with_par)
diff --git a/R/oxfordtheme.R b/R/oxfordtheme.R
index fc2b05d..b242b13 100644
--- a/R/oxfordtheme.R
+++ b/R/oxfordtheme.R
@@ -13,5 +13,6 @@
 #' @importFrom stringr str_pad
 #' @importFrom grDevices col2rgb rgb colorRampPalette
 #' @importFrom graphics rect par image text
+#' @importFrom withr with_par
 #'
 "_PACKAGE"
diff --git a/R/utils.R b/R/utils.R
index 5e66f5c..5dc0fd8 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -46,9 +46,14 @@ print.palette <- function(x, ...) {
   # old <- par(mar = c(0.5, 0.5, 0.5, 0.5))
   # on.exit(par(old))
 
-  image(1:n, 1, as.matrix(1:n), col = x,
-        ylab = "", xaxt = "n", yaxt = "n", bty = "n")
+  withr::with_par(
+    new = list(mar = c(0.5, 0.5, 0.5, 0.5)),
+    code = {
+      image(1:n, 1, as.matrix(1:n), col = x,
+            ylab = "", xaxt = "n", yaxt = "n", bty = "n")
 
-  rect(0, 0.9, n + 1, 1.1, col = rgb(1, 1, 1, 0.8), border = NA)
-  text((n + 1) / 2, 1, labels = attr(x, "name"), cex = 1, family = "serif")
+      rect(0, 0.9, n + 1, 1.1, col = rgb(1, 1, 1, 0.8), border = NA)
+      text((n + 1) / 2, 1, labels = attr(x, "name"), cex = 1, family = "serif")
+    }
+  )
 }
diff --git a/README.Rmd b/README.Rmd
index 6d811ac..c2b472a 100644
--- a/README.Rmd
+++ b/README.Rmd
@@ -61,7 +61,7 @@ oxford_colours |>
   knitr::kable()
 ```
 
-```{r oxford-colours-graphic, echo = FALSE, fig.height = 1}
+```{r oxford-colours-graphic, echo = FALSE, fig.height = 1, fig.align = "center"}
 structure(get_oxford_colours() |> (\(x) x[x != ""])(), class = "palette", name = "Oxford Colours")
 ```
 
@@ -87,7 +87,7 @@ Based on the [University of Oxford](https://ox.ac.uk)'s [visual identity guideli
 oxford_theme_palettes()$heritage
 ```
 
-```{r oxford-palettes-heritage-show, echo = FALSE, fig.height = 1}
+```{r oxford-palettes-heritage-show, echo = FALSE, fig.height = 1, fig.align = "center"}
 structure(oxford_theme_palettes()$heritage, class = "palette", name = "heritage")
 ```
 
@@ -97,7 +97,7 @@ structure(oxford_theme_palettes()$heritage, class = "palette", name = "heritage"
 oxford_theme_palettes()$contemporary
 ```
 
-```{r oxford-palettes-contemporary-show, echo = FALSE, fig.height = 1}
+```{r oxford-palettes-contemporary-show, echo = FALSE, fig.height = 1, fig.align = "center"}
 structure(oxford_theme_palettes()$contemporary, class = "palette", name = "contemporary")
 ```
 
@@ -107,7 +107,7 @@ structure(oxford_theme_palettes()$contemporary, class = "palette", name = "conte
 oxford_theme_palettes()$celebratory
 ```
 
-```{r oxford-palettes-celebratory-show, echo = FALSE, fig.height = 1}
+```{r oxford-palettes-celebratory-show, echo = FALSE, fig.height = 1, fig.align = "center"}
 structure(oxford_theme_palettes()$celebratory, class = "palette", name = "celebratory")
 ```
 
@@ -117,7 +117,7 @@ structure(oxford_theme_palettes()$celebratory, class = "palette", name = "celebr
 oxford_theme_palettes()$corporate
 ```
 
-```{r oxford-palettes-corporate-show, echo = FALSE, fig.height = 1}
+```{r oxford-palettes-corporate-show, echo = FALSE, fig.height = 1, fig.align = "center"}
 structure(oxford_theme_palettes()$corporate, class = "palette", name = "corporate")
 ```
 
diff --git a/README.md b/README.md
index 797ab5b..4d69a1a 100644
--- a/README.md
+++ b/README.md
@@ -96,7 +96,7 @@ the following colours are available from this package:
 | Gold                 |               |                 |          | 10122C        |
 | Silver               |               |                 |          | 10103C        |
 
-![](man/figures/README-oxford-colours-graphic-1.png)<!-- -->
+<img src="man/figures/README-oxford-colours-graphic-1.png" style="display: block; margin: auto;" />
 
 You can access either the name, RGB, CMYK, hex code, and/or Pantone
 values of each Oxford colour through the `get_oxford_colours()` function
@@ -136,7 +136,7 @@ oxford_theme_palettes()$heritage
 #> [1] "#994636" "#E08D79" "#C4A29E" "#A0AF84" "#426A5A"
 ```
 
-![](man/figures/README-oxford-palettes-heritage-show-1.png)<!-- -->
+<img src="man/figures/README-oxford-palettes-heritage-show-1.png" style="display: block; margin: auto;" />
 
 #### Contemporary
 
@@ -145,7 +145,7 @@ oxford_theme_palettes()$contemporary
 #> [1] "#FE615A" "#ED9390" "#E4F0EF" "#789E9E" "#00AAB4"
 ```
 
-![](man/figures/README-oxford-palettes-contemporary-show-1.png)<!-- -->
+<img src="man/figures/README-oxford-palettes-contemporary-show-1.png" style="display: block; margin: auto;" />
 
 #### Celebratory
 
@@ -154,7 +154,7 @@ oxford_theme_palettes()$celebratory
 #> [1] "#15616D" "#776885" "#E2C044" "#D4CDF4" "#7F055F"
 ```
 
-![](man/figures/README-oxford-palettes-celebratory-show-1.png)<!-- -->
+<img src="man/figures/README-oxford-palettes-celebratory-show-1.png" style="display: block; margin: auto;" />
 
 #### Corporate
 
@@ -163,7 +163,7 @@ oxford_theme_palettes()$corporate
 #> [1] "#FB5607" "#B9D6F2" "#95C11F" "#49B6FF" "#1D42A6"
 ```
 
-![](man/figures/README-oxford-palettes-corporate-show-1.png)<!-- -->
+<img src="man/figures/README-oxford-palettes-corporate-show-1.png" style="display: block; margin: auto;" />
 
 ### Oxford theme paletttes for use in plotting