Update use of Sass variables for better theming

Use Bootstrap color functions for theme-colors and grays instead
of directly referencing Sass variable to allow more flexible
theming.

Signed-off-by: Yoshie Muranaka <yoshiemuranaka@gmail.com>
Change-Id: Id08b77ff6df3bdf99400dcdfe964853706f1070f
diff --git a/src/assets/styles/bmc/custom/_pagination.scss b/src/assets/styles/bmc/custom/_pagination.scss
index 4fed21b..0c2ac85 100644
--- a/src/assets/styles/bmc/custom/_pagination.scss
+++ b/src/assets/styles/bmc/custom/_pagination.scss
@@ -12,9 +12,9 @@
 
 .b-pagination {
   .page-item.active button {
-    color: $dark;
+    color: theme-color("dark");
     background-color: $white;
     border-color: $border-color;
-    box-shadow: inset 0px -3px $primary;
+    box-shadow: inset 0px -3px theme-color("primary");
   }
 }
\ No newline at end of file