The choice of blaze orange, chartreuse (yellow-green) or pure white has been studied by human factors experts for other applications such as signage and transportation. While we are not aware of any studies for diving applications, those other studies and our own experience provide good guidance for our recommendations. Choose orange for maximum visibility in well lighted conditions, choose pure white for absolute maximum contrast in very low-light conditions. In our opinion, your best compromise choice for all conditions is the chartreuse yellow-green color.