Interesting suggestion!

Part of the game's design philosophy is that players will understand how items work and if an item's functionality is altered, it should be telegraphed to the player in some way (that's why Nudges are not invisible, for example).

We don't want players to (potentially) instantly explode from a Halcyon which is considered 'safe' until it starts to shake and alerts it's imminent explosion - However, if the Halcyon looked somewhat different (glowing red for example), players could learn that in that state it can explode at any time without warning.

We'll definitely consider this suggestion!