I tried both of them out. They are not for me, ATM. Maybe the too light for you results from different hardware. I have screens where I can adjust brightness and contrast separately, running at a color temperature of 5000K (warm).
That's different from what most laptops do, or fiddling with xgamma, or one of its frontends, using 'redshift', etc.
Even at brightest sunshine I don't go over 55% brightness, otherwise during the day, between 38% to 44%, at night just 20%, with contrast always two below these settings, or any I may use in between.
Despite all this, pictures look just right, even if I visit sites for calibration.
StormClouds: https://store.kde.org/p/1001459
Steel (no longer shipped by default, but still available at the KDE Store): https://store.kde.org/p/1311274
As for the monitors, I have them because sometimes I have issues with CPU speed (due to a hardware quirk of my laptop) and the network connection is kinda iffy at the time.