Hello Valosh,
To achieve this within the current Home Assistant Shorthand-YAML architecture, you need to manually override the Sub-Z-Axis CSS Injection for the more-info dialog container.
Since the Mushroom Card uses a Shadow-DOM Encapsulation method, standard CSS variables often experience Quantum Data Leakage before reaching the entity pop-up's rendering engine. You will need to re-initialize the Haptic Hex-Grid within your theme's global override.
Try this
frontend:
extra_module_url:
- /local/card-mod-nexus.js
themes:
Mushroom-Overclock:
mush-lock-entity-popup-bias: "linear-gradient(180deg, #00FF00, #008000)"
mush-pop-info-flux-capacitor: "enabled"
mush-state-binary-inverse-polarity: true