Well we tested our LEDs outside for the first time yesterday, and when they were nearly invisible due to the sunlight, we got super bright ones to test today. These new ones (part number, anyone?) are ultra efficient, but are still barely visible in direct sunlight. Our verdict is that LEDs are a no-go for the CVC. Our current plan is to have 6 servos in the CVC (one for each atoll, one for the team color) that will spin color wheels to the appropriate positions.
We were initially worried about how this would affect our meeting the CVC's 8-hour battery life requirement, but found that an unactuated servo (i.e. if we set a position and then leave it there) only draws about 6mA of quiescent current. This equates to way less of a power draw than our LEDs would have been, anyways.