chore: update images color to pick variables

Author: OlufunkeMoronfolu

assets/scss/_styles_project.scss

@@ -257,7 +257,7 @@ div.date-format{
 
 // DB – Add borders around images
 main img {
-    border-color: #d7d7d7;
+    border-color: $gray-400;
     border-width: 1px;
     border-style: solid;
 }