Mark supervised users in the "Users" list in about:settings.

chrome/browser/resources/options/browser_options.css

Index: chrome/browser/resources/options/browser_options.css
diff --git a/chrome/browser/resources/options/browser_options.css b/chrome/browser/resources/options/browser_options.css
index ac9230d6714481dfef832f992e59d66ab5c91abe..e66b0d04d3928bbe59595cb8a8002e50e87a9e8b 100644
--- a/chrome/browser/resources/options/browser_options.css
+++ b/chrome/browser/resources/options/browser_options.css
@@ -87,6 +87,13 @@ html[dir=rtl] #account-picture-wrapper {
   min-height: 0;
 }
 
+#profiles-list .profile-container {
+  -webkit-box-align: center;
+  display: -webkit-box;
+  max-width: 100%;
+  white-space: nowrap;

[Patrick Dubroy, 2014/04/03 10:48:39]

I don't think you need this.

[Marc Treib, 2014/04/03 11:41:56]

Done.

+}
+
 #profiles-list .profile-name {
   -webkit-box-flex: 1;
   overflow: hidden;
@@ -94,6 +101,12 @@ html[dir=rtl] #account-picture-wrapper {
   white-space: nowrap;
 }
 
+#profiles-list .profile-supervised {
+  color: gray;

[Patrick Dubroy, 2014/04/03 10:48:39]

I don't see "gray" anywhere else in this file. Usually we use rgb or hex values
for colors...is there another element on this page with the same color that you
could be consistent with?

[Marc Treib, 2014/04/03 11:41:56]

I don't see another "gray for de-emphasis" anywhere else on the page, and
reusing a "gray for disabled" color doesn't make much sense. I could just
replace it by, say, #777 if named colors are discouraged in general? ("white"
and "black" do appear in this file, though!)

[Patrick Dubroy, 2014/04/03 11:48:38]

Actually, we seem to use #999 in a few places (e.g., policy-controlled
settings), and in the sidebar menu. Maybe this should be the same?

[Marc Treib, 2014/04/03 12:01:08]

Done.

+  margin-left: 5px;
+  white-space: nowrap;

[Patrick Dubroy, 2014/04/03 10:48:39]

Ditto.

[Marc Treib, 2014/04/03 11:41:56]

Done.

+}
+
 #profiles-list > * {
   height: 40px;
 }