theme: transparent dash
In the current version of GNOME, the dash uses a solid color. While there's nothing wrong with the current design, there's no question that it could be better. See video below.
Screencast_from_03-25-2022_08_55_18_PM
Notice the transparent dash and the inclusion of a gradient? This looks especially good on a laptop with track pad gestures. Here's how I got this working by modifying the shell css:
#dash {
background-gradient-start: rgba(35, 35, 35, 0);
background-gradient-end: #232323;
background-gradient-direction: vertical; }
.dash-background {
background-color: rgba(255, 255, 255, 0.1); }
To my eye, the gradient is more pleasant than the harsh cutoff created by the dash using the current style.