[NIFI-6447] update demo theme accent color

This closes #35
diff --git a/webapp/theming/fds-demo.scss b/webapp/theming/fds-demo.scss
index 3e9541e..59217e9 100644
--- a/webapp/theming/fds-demo.scss
+++ b/webapp/theming/fds-demo.scss
@@ -29,8 +29,8 @@
 //Change these
 $primaryColor: $rose1;
 $primaryColorHover: $rose2;
-$accentColor: $blue7;
-$accentColorHover: $grey4;
+$accentColor: $blue-grey1;
+$accentColorHover: $blue-grey2;
 
 // Include the base styles for Angular Material core. We include this here so that you only
 // have to load a single css file for Angular Material in your app.