Well it turns out that in particular circumstances, that 40-50% increase in detection time does matter, and CVD drivers are over-represented in rear-end collisions at traffic lights. Not a lot higher, and they are usually low speed, but the data is clear. Simple system, the light is on or off, and there is redundancy built into the system (standard position of the lights).
Clearly, then, CVD pilots should be prohibited from taxiing aircraft on the roads.
Seriously: Is this the quality of the logic justifying the recent change?
Where is the data to which you refer, and where is the evidence proving causation rather than correlation? When was the last time a policeman asked the driver involved in a rear-ender, do you have CVD? How could this data be collected?
The message is still there, but the time to detect it may change. Whether that actually matters or not depends on the system and the circumstance.
So in which system/s does it matter?
If that change of colour has any safety-critical implications, it's badly designed system. The history of aviation is littered with systems that seemed brilliant in theory but caught out many perfectly competent pilots in practice.