Several regular contributors to this website have talked about smoke diminishing the color in displays. Putting on my college professor cap, I'd like to point out that this is not strictly accurate. Because it blocks light smoke can reduce brightness and in extreme cases totally hide displays (e.g. Vulcan, 2015), but so-long as it is 'neural density' (i.e. grey) moderate smoke should have no effect on the range of colors presented.

Smoke has its major impact because its acts as a 'low-pass spatial frequency filter' that removes object details. In people-speak, it makes everything fuzzy, so that points of light become diffuse blurs and can blend into one-another. Consider what this will do to a kamuro or willow. Moreover, by spreading diffuse light into dark regions it reduces the visual contrast between the burning stars and surrounding black of the night sky. This can have a huge adverse effect on a show's visual aesthetics but will not alter its color profile.

Hi Robert,

Yes, that is true. It is generally the atmospheric moisture concentration that affects color richness/brightness directly. While sometimes referring to the smoke negatively affecting color richness in my weather reports and reviews, this was not meant to be implied as a direct cause in drowning colors in the strictest sense, but rather how a given show’s color vibrancy would likely “appear” to viewers in a situation where smoke accumulation is significant and/or displacing unfavorably towards them. As a result, the effect of smoke on fireworks colors is more optically-related, as opposed to the smoke being a direct impact on the colors themselves (as you mentioned above), since it essentially hides the fireworks over time.

Whenever relevant, it is mentioned in the weather reports that if the “humidity” is high enough (i.e. often when surface dewpoints are 18 Celsius or higher) and/or if the air is (near-) saturated or damp, then overall color richness would be more negatively affected. The influence of high/very high humidity is actually two-fold, as larger humidity concentrations also encourage a higher degree of smoke build-up, which, in turn, affects viewing, especially if the wind direction is unfavorable and wind speeds are weak.

So long as such environments are present, even if there is sufficient wind speed to clear the smoke quickly enough, color quality could still be affected more noticeably than it otherwise would in a scenario where the humidity is considerably lower. While certain colors will be less impacted than others, these conditions are notably influential on already dimmer hues, such as deeper, darker blues or charcoal-variety fireworks.

Trav.