Beacon devices support custom colors in badge mode, however if you enable the hud/badge in the settings of a ball_spawner_device it does not support a custom color (badge is automatically colored blue, green, orange based on friendly, neutral, hostile team relationship). Would be nice to be able to set a direct color just like in the standalone badge beacon.
Thank you for your feedback. While I cannot guarantee a response, I can confirm that this has been forwarded to the appropriate team.