I know this is a really old thread but was something I found interesting so did a bit of searching and come across this if anyone want to read it
WorkSafeBC.com
Key findings
Following extensive laboratory simulations and on-water experiments, the researchers found that fluorescent green, followed by fluorescent orange, were the most conspicuous colors for a floating target when compared to nonfluorescent red and non-fluorescent yellow.
Objectives
This study was designed to identify and scientifically validate the most conspicuous colour for use on personal flotation devices and immersion suits when viewed on the water. The researchers compared three Pantone colours and one high visibility, fluorescent pigmented material on the basis of contrast and conspicuity to determine the combination of colours and luminance that would be most visible to the human eye under the majority of real-world conditions. It was the researchers’ assertion that colours with the greatest difference in luminance and chromaticity from the water and horizon would provide the most contrast and would as a result be the most visible. The ultimate goal of this study was to share the knowledge gained from the research to maritime workers to help everyone make informed decisions about safety.
So basically what everyone concluded is exactly right and someone did the actual science to prove it.