As a former competitive speedcuber, I basically had to do something similar but I went with a fluorescent orange (and fluorescent green to distinguish from blue

As a former competitive speedcuber, I basically had to do something similar but I went with a fluorescent orange (and fluorescent green to distinguish from blue) rather than black. At a slow speed it isn't much of an issue but when speedsolving, blue-green and red-orange take just a bit too long to distinguish even for my human eyes.