You might look at it in another way. Bright green is a bit unusual for a lock suggesting to the potential thief that the particular lock might not be a run of the mill. It could be that the thief would have a second thought working against that lock as compared to a black one.

Myself I have a bright green one but may main motivation was to stick to a scheme where smaller items that belong to me are in that color so it is to easier for me to fish them out from the surrounding when I take off and need to take the items along. My wife's items are in bright orange for a similar reason.