Can I set a custom white balance on green leaves with a 550 nm infrared filter?
You can white balance on green leaves with high-pass filters from 590–740 nm. It would be best to avoid white balancing on green leaves with high-pass filters using a cut-off of 560 nm or lower. Avoid foliage for white balancing with these filters and use color-neutral subjects for white balancing.
High-pass filters with a cut-off of 560 nm or lower allow some visible green light to pass. Foliage is no longer color-neutral compared to higher-numbered high-pass filters since it will reflect green light in addition to infrared.
White balancing on green foliage only works well with high-pass filters that do NOT capture visible green light. When the green light is blocked, foliage only reflects infrared light, which is color neutral. Filters with a high-pass of 590–740 nm can use green foliage as a white balance subject.
See examples in this video.