I know you're able to change it when you have a clock above them, you just click on it while you're editing the lockscreen, and it allows you to change the font, style, and color, and it will also change the color of the widgets. So maybe you can add a clock to change the color and take it away again?
There should be an option to change the style and color when you're editing the lockscreen....hmm maybe trying downloading Good Lock through the galaxy store and then install lockstar it may give you the option then
