Update macosx/README

1 files changed, 16 insertions, 13 deletions

diff --git a/macosx/README b/macosx/README
index e9d50a4..6f3926f 100644
--- a/macosx/README
+++ b/macosx/README
@@ -272,21 +272,24 @@ appearance.  Part of the implementation of the Dark Mode was to make
 some of the named NSColors have dynamic values.  Apple calls these
 "semantic colors" because the name does not specify a specific color,
 but rather refers to the context in which the color should be used.
-Tk now provides the following semantic colors as system colors:
-systemTextColor, systemTextBackgroundColor, systemSelectedTextColor,
-systemSelectedTextBackgroundColor, systemControlTextColor,
-systemDisabledControlTextColor, systemLabelColor, systemLinkColor,
-systemControlAccentColor, and systemPlaceholderTextColor.  All of these
-except the last four were present in OSX 10.0 (and those four are
-simulated in systems where they do not exist).  The change in 10.14 was
-that the RGB color value of these colors became dynamic, meaning that
-the color value can change when the application appearance changes.
 In particular, when a user selects Dark Mode in the system preferences
 these colors change appearance.  For example systemTextColor is dark in
-Aqua and light in DarkAqua.  One additional color,
-systemSelectedTabTextColor, does not exist in macOS but is used by Tk
-to match the different colors used for Notebook tab text in different
-OS versions.
+Aqua and light in DarkAqua.
+
+Tk now provides colors corresonding to all of the NSColors in Apple's System
+ColorList.  The convention for naming these colors is that the Tk name is
+generated by capitalizing the macOS name and adding the prefix "system". The
+System ColorList differs between releases of macOS and some colors, such as
+systemLinkColor and systemControlAccentColor, are simulated on older systems
+which did not provide them.  The following colors are available on all
+supported macOS releases, although newer systems will support additional
+colors: systemControlAccentColor, systemControlTextColor,
+systemDisabledControlTextColor, systemLabelColor, systemLinkColor,
+systemPlaceholderTextColor, systemSelectedTextBackgroundColor,
+systemSelectedTextColor, systemSeparatorColor, systemTextBackgroundColor, and
+systemTextColor.  One additional color, systemSelectedTabTextColor, does not
+exist in macOS but is used by Tk to match the different colors used for
+Notebook tab titles in different OS versions.
 
 The default background and foreground colors of most of the Tk widgets
 have been set to semantic colors, which means that the widgets will change