Give Heartbeat your colors.
Pick the colors, check them on a live copy of the dashboard and paste the CSS into Settings. Everything happens in your browser.
Start from
Contrast with the background
Main text
Muted text
Heartbeat
Dashboard
Logs
Apps
searchDown: DNS lookup failed
Needs attention
Response time142 ms
ERROR search::http request failed WARN search::db slow query 2380 ms INFO search::http request completed
Your theme
Apply it
In Heartbeat, open Settings and find Custom theme.
Paste the CSS or load the .css file, and save.
In the top bar, choose Custom from the theme menu.
Only an admin can save the theme. Each person picks Custom in their own browser.