I don't think hundreds of hours of testing went into anything for the html spec back in the 90's. Things were quite ad hoc in the early days! That said, there

I don't think hundreds of hours of testing went into anything for the html spec back in the 90's. Things were quite ad hoc in the early days! That said, there were probably specific reasons why those colors were chosen, reasons that might not make so much sense today. Oh I remember - it's to fit into the 256 colour palette of gifs and old school graphics adapters that can't store too many bits! If you wanted more colours, you had to swap out the pallette. I don't think that applies today anymore, even on the most basic computers.