diff --git a/vncviewer_unix/CConn.cxx b/vncviewer_unix/CConn.cxx
index 519d540..ec2f014 100644
--- a/vncviewer_unix/CConn.cxx
+++ b/vncviewer_unix/CConn.cxx
@@ -683,7 +683,7 @@
   // Select best color level
   newFullColour = (kbitsPerSecond > 256);
   if (newFullColour != fullColour) {
-    vlog.info("Throughput %d kbit/s - full colour is now %s", 
+    vlog.info("Throughput %d kbit/s - full color is now %s", 
 	      kbitsPerSecond,
 	      newFullColour ? "enabled" : "disabled");
     fullColour = newFullColour;
diff --git a/vncviewer_unix/OptionsDialog.h b/vncviewer_unix/OptionsDialog.h
index 88f1c8b..561bad2 100644
--- a/vncviewer_unix/OptionsDialog.h
+++ b/vncviewer_unix/OptionsDialog.h
@@ -40,14 +40,14 @@
 public:
   OptionsDialog(Display* dpy, OptionsDialogCallback* cb_)
     : TXDialog(dpy, 400, 450, "VNC Viewer: Connection Options"), cb(cb_),
-      formatAndEnc(dpy, "Encoding and Colour Level:", this),
+      formatAndEnc(dpy, "Encoding and Color Level:", this),
       inputs(dpy, "Inputs:", this),
       misc(dpy, "Misc:", this),
       autoSelect(dpy, "Auto select", this, false, this),
-      fullColour(dpy, "Full (all available colours)", this, true, this),
-      mediumColour(dpy, "Medium (256 colours)", this, true, this),
-      lowColour(dpy, "Low (64 colours)", this, true, this),
-      veryLowColour(dpy, "Very low (8 colours)", this, true, this),
+      fullColour(dpy, "Full (all available colors)", this, true, this),
+      mediumColour(dpy, "Medium (256 colors)", this, true, this),
+      lowColour(dpy, "Low (64 colors)", this, true, this),
+      veryLowColour(dpy, "Very low (8 colors)", this, true, this),
       tight(dpy, "Tight", this, true, this),
       zrle(dpy, "ZRLE", this, true, this),
       hextile(dpy, "Hextile", this, true, this),
diff --git a/vncviewer_unix/vncviewer.cxx b/vncviewer_unix/vncviewer.cxx
index 77443e7..29679b8 100644
--- a/vncviewer_unix/vncviewer.cxx
+++ b/vncviewer_unix/vncviewer.cxx
@@ -58,13 +58,14 @@
                               "invisible cursor", true);
 BoolParameter autoSelect("AutoSelect",
                          "Auto select pixel format and encoding", true);
-BoolParameter fullColour("FullColour",
-                         "Use full colour", true);
-AliasParameter fullColor("FullColor", "Alias for FullColour", &fullColour);
-IntParameter lowColourLevel("LowColourLevel",
-                            "Colour level to use on slow connections. "
-                            "0 = Very Low (8 colours), 1 = Low (64 colours), "
-                            "2 = Medium (256 colours)", 2);
+BoolParameter fullColour("FullColor",
+                         "Use full color", true);
+AliasParameter fullColourAlias("FullColour", "Alias for FullColor", &fullColour);
+IntParameter lowColourLevel("LowColorLevel",
+                            "Color level to use on slow connections. "
+                            "0 = Very Low (8 colors), 1 = Low (64 colors), "
+                            "2 = Medium (256 colors)", 2);
+AliasParameter lowColourLevelAlias("LowColourLevel", "Alias for LowColorLevel", &lowColourLevel);
 StringParameter preferredEncoding("PreferredEncoding",
                                   "Preferred encoding to use (ZRLE, hextile or"
                                   " raw) - implies AutoSelect=0", "");
diff --git a/vncviewer_unix/vncviewer.man b/vncviewer_unix/vncviewer.man
index 4c67aa5..f5890a4 100644
--- a/vncviewer_unix/vncviewer.man
+++ b/vncviewer_unix/vncviewer.man
@@ -34,13 +34,13 @@
 .SH AUTOMATIC PROTOCOL SELECTION
 
 The viewer tests the speed of the connection to the server and chooses the
-encoding and pixel format (colour level) appropriately.  This makes it much
+encoding and pixel format (color level) appropriately.  This makes it much
 easier to use than previous versions where the user had to specify arcane
 command line arguments.
 
-The viewer normally starts out assuming the link is slow, using a low colour
+The viewer normally starts out assuming the link is slow, using a low color
 level and using the encoding with the best compression.  If it turns out that
-the link is fast enough it switches to full-colour mode and will use an
+the link is fast enough it switches to full-color mode and will use an
 encoding which compresses less but is faster to generate, thus improving the
 interactive feel.  Automatic selection can be turned off by setting the
 \fBAutoSelect\fP parameter to false, or from the options dialog.
@@ -131,18 +131,18 @@
 encoding and pixel format appropriately.  Turn it off with \fB-AutoSelect=0\fP.
 
 .TP
-.B \-FullColour, \-FullColor
-Tells the VNC server to send full-colour pixels in the best format for this
-display.  By default a low colour mode is used until AutoSelect decides the
+.B \-FullColor, \-FullColour
+Tells the VNC server to send full-color pixels in the best format for this
+display.  By default a low color mode is used until AutoSelect decides the
 link is fast enough.  However if the server's native pixel format is
-colourmapped (as opposed to truecolour) then the server's format is used by
+colormapped (as opposed to truecolor) then the server's format is used by
 default.
 
 .TP
-.B \-LowColourLevel \fIlevel\fP
-Selects the reduced colour level to use on slow links.  \fIlevel\fP can range
-from 0 to 2, 0 meaning 8 colours, 1 meaning 64 colours (the default), 2 meaning
-256 colours.
+.B \-LowColorLevel, \-LowColourLevel \fIlevel\fP
+Selects the reduced color level to use on slow links.  \fIlevel\fP can range
+from 0 to 2, 0 meaning 8 colors, 1 meaning 64 colors (the default), 2 meaning
+256 colors.
 
 .TP
 .B \-PreferredEncoding \fIencoding\fP