No. It cant be changed.Even when you have acknowledged, the status is maintained so that when a normal event arrives for the same object(ie volume/qtree/filer etc) it can be neutralized and its status changes to green.
There is one other possibility where you can change the severity of the event it self so that the color doesnt change.
For example, a volume's capacity has 3 events,
volume Full
volume NearlyFull
volume Normal.
Of these full event has a status color of red, nearly full yellow and normal green.
If you are not bothered by the Nearly full event you can the event severity to Information/Normal so that its status color remains green instead of yellow.
so in a way the status color stays green.
Regards
adai