Custom color for data usage text in notification panel and in float notifications.

The data usage text (in notification panel, under the buttons) is always black. If I change notification panel background color to black, that text can't be seen.

The colors of float notifications text and background might be also be customized. I think text color of this float notifications uses same color of text color of the notification panel, but the background is always white, I mean, if I choose black for the notification panel background then the text of the notifications, in the panel, is white, but also turns to white the text of the float notifications, so it can't be read as thos float notifications have white background.

(I use Google Now Launcher -Pixel version)