Increase subtab contrast

Supposed to fix #1271.

Should probably go a bit higher in contrast still, but also
did not want to risk deviating from the general style too much.

Author: Arnei

src/components/events/partials/ModalTabsAndPages/EventDetailsAssetsTab.tsx

@@ -91,13 +91,13 @@ const EventDetailsAssetsTab = ({
 		padding: "14px 5px",
 		fontWeight: "600",
 		minWidth: "100px",
-		color: "#5d7589",
+		color: "#435263",
 	};
 
 	const assetsTabInactive = {
 		padding: "14px 5px",
 		minWidth: "100px",
-		color: "#92a0ab",
+		color: "#646e75",
 	};
 
 	useEffect(() => {

src/styles/base/_variables.scss

@@ -82,7 +82,7 @@ $light-black-alpha:            rgba($black, 0.04);
 // ----------------------------------------
 
 $body-background:               $off-white;
-$header-link-color:             #596C82;
+$header-link-color:             #435263;
 $color-link:                    $medium-prim-color;
 $color-link-hover:              $dark-prim-color;