This guide is based on the KK 4.4.2 Galaxy S5 builds.
I noticed that Samsung always make the statusbar notification areas a bit dim. Probably to help with battery conservation.
This requires decompiling SystemUI.apk.
Change these three lines New values are in BLUE <item type="dimen" name="status_bar_icon_drawing_alpha">100.0%</item> <item type="dimen" name="system_icon_area_alpha">1.0</item> <item type="dimen" name="notification_icon_area_alpha">1.0</item>
Screenshots are best viewed from a PC so you can rapidly swap images to see the difference.