When did the cove line give way to the go-faster stripe?!

I was struck, once again, by the sober elegance of a properly painted coveline. This one is on a 1980 Kim Holman-designed Twister 28 (the GRP version of his original, wooden Twister). The boat was recently and quite comprehensively restored, and on a recent visit to sound her out our for an owner with a few to a pre-purchase survey, I found myself wondering: exactly when did off-white and dark blue hulls with painted, gold-coloured cove lines give way to toothpaste-white hulls with brightly-coloured go-faster stripes?!