Quite possibly other preferences are aesthetic except in rare pathological cases. There have been many suggestions made as to the most visible contrast alternatives, most often based on very dubious theory. Other factors contributing to legibility must be considered too. The more different each letter is from those around it the fewer errors will occur. Decorated letters will fuse and create noise in the system.
Script is considerably more difficult than standard print.
Aesthetic qualities, while theoretically not very important, will in practice have a considerable effect on any individual's desire to read for long periods. The project was limited to white characters on a black background. However other colours are used in subtitling to indicate a change of speaker, but time constraints in the first phase of this project did not permit testing with various colours. The weight of the characters, i.e. the thickness of the character strokes. If the weights are too thin there will not be sufficient contrast.