Style improvements for template previews

src/_colors.scss

@@ -130,6 +130,10 @@ $toolbar-button-disabled: $gray-lighten-30;
 
 $background-dark-elevated: #2e2e2e;
 $background-dark-secondary: #1e2327;
+
+// Primary tint color (light)
+$blue-50: #2271b1;
+// Primary tint color (dark)
 $blue-30: #5198d9;
 
 // color-studio
@@ -140,6 +144,7 @@ $gray-20: #a7aaad;
 $gray-30: #8e9196;
 $gray-40: #787c82;
 $gray-50: #646970;
+$gray-60: #50575e;
 $gray-70: #3c434a;
 $gray-90: #1d2327;
 $gray-95: #1d2327;