It's not so simple as choosing a color and minibar. You have to show light output at 19 test points for each of the 4 zones, as well as 5 degrees up and down at each test point, to be NFPA compliant. This costs money for engineers to determine, that's why they have pre-approved packages in all the manufacturers NFPA catalogs. You can't just slap a couple of lightheads on there and say it's compliant because the colors are correct.
For example, for SMALL APPARATUS for CALLING FOR RIGHT OF WAY the requirement for Zone A (front) is 1.000,000 candela-seconds/minute for the total of all 19 test points in the horizontal plane, with 10,000 candela-seconds/minute minimum in any one of the 19 test points and 3,500 candela-seconds/minute plus or minus 5 degrees from horizontal minimum for any of the 19 test points.
From the Whelen catalog:
How to Measure Lighting Specifications
EXAMPLE: Zone A Upper, Clearing the Right of Way Measurements.
1. Test all modules distributing light 45° right and 45° left at 5° increments (19 test points, total).
2. Add all 19 test points together for each module and add these modules together.
For example:
A rotating lamp has the same reading at all 19 points
(i.e. 120 candela seconds in red) 19 x 120 = 2280.
There are four of these identical rotators in Zone A 4 x 2280 = 9120.
There is also one clear rotator in Zone A that produces 600 candela. 19 x 600 x 1 = 11400.
Add 11400 to the four identical rotators (9120) for a total of 20520.
To convert to candela-second/minutes, multiply 20520 x 1.25 (Hz) x 60 (seconds).
The total is 1,539,000 candela-second/minutes.
3. There is a minimum requirement in Zone A for each of the 19 test points (10,000 candela-sec./min.).
For example: 20° left:
Four red rotators produce 220 candela seconds at 20° and one clear rotator produces 600 candela
seconds at 20° for a total of 1080 candela seconds. Multiply 1080 by 1.25 (Hz) and multiply by 60
(seconds) for a total of 81,000 candela-second/minutes.
4. The final test requirement for this zone is to check 5° up and 5° down at all 19 test points.
The minimum requirement for these areas is 3500 candela-second/minutes.
For example: at 35° left, 5° down:
All four identical red rotators get 40 candela seconds.
One clear rotator gets 200 candela seconds.
40 x 4 + 200 x 1.25 (Hz) x 60 (seconds) equals 27,000 candela-second/minutes