Tab icons are hard to see using the dark theme and low bright in the screen

Detailed description of the problem: The tabs icons (some highlighted in red in the attached photo) are really hard to see using a dark theme, specially if you are using it with the phone in low light as it could be expected from this app as it is used before going to sleep.

Steps to reproduce: Have the dark theme enabled and tabs on top

Version of Sleep as Android: 20200808

Suggestion: At least the icons should be bold white like the text shown in the image.