For what it’s worth, publicly accessible pull stations are also not required in most occupancies if sprinkler protection is provided and a single pull station is accessible to staff. IBC only prohibits the use of the sprinkler exception in the following occupancies:
- Group H-5
- Group I (excluding patient sleeping areas in I-1 and I-2 and detainee areas of I-3)
- Aerosol product rooms and warehouses (this may or may not have the sprinkler exception)
- Lumber, wood structural panel and veneer mills
- Deep underground buildings (>60 feet below exit discharge level)
NFPA 101 prohibits the use of the sprinkler exception in the following occupancies:
- Day care
- Health care (excluding patient sleeping areas)
- Ambulatory health care
- Existing lodging or rooming houses without fire alarm systems (where the pull station must be connected to the smoke alarms)
- New hotels and dormitories
- Apartment buildings with more than 4 stories or 16 dwelling units
- Residential board and care
These are generally not the occupancies that would benefit from heavily decorated walls near the exits, so I doubt there would be much to gain by changing the color of the pull stations. In other occupancies, it should be fine if voluntarily provided pull stations don’t meet the requirements for standing out, since that is unlikely to cause any hazard (unlike fake pull stations).