Achieving White Light / Additive / Subtractive mixing.
124 Dark Green
164 Flame Red
119 Dark Blue
To achieve white light (or neutrality) using 3 secondary colours on a single source (subtractive colour mixing) we recommend:
101 Yellow
115 Peacock Blue
128 Bright Pink
Results will vary depending on conditions and the type of light source, however the filters listed above will act as a good starting point and give acceptable results in most circumstances.