Import Font and Color from traitsui, not traits (#558)

This PR updates an example to import the `Font` and `Color` trait types
from `traitsui.api` instead of from `traits.api`. The `Font` and `Color`
traits in `traits.api` are deprecated.

CHANGES.rst

@@ -7,12 +7,14 @@ Version 7.0.1
 
 Released: 2023-03-24
 
-This is a bugfix release whose sole purpose is to fix the Read the Docs
+This is a bugfix release whose main purpose is to fix the Read the Docs
 build for the Envisage documentation.
 
 Fixes
 -----
 * Fix the documentation build for Read the Docs. (#560)
+* Fix example code that was importing ``Font`` and ``Color`` from Traits
+  instead of TraitsUI. (#558)
 
 
 Version 7.0.0

examples/legacy/workbench/AcmeLab/acme/workbench/acme_preferences_page.py

@@ -13,8 +13,8 @@
 
 # Enthought library imports.
 from apptools.preferences.ui.api import PreferencesPage
-from traits.api import Color, Float, Font, Int
-from traitsui.api import View
+from traits.api import Float, Int
+from traitsui.api import Color, Font, View
 
 
 class AcmePreferencesPage(PreferencesPage):