Roy Seburn was one of the Merry Pranksters , famous for painting the Further logo on the bus.
He didn't travel aound in the bus so wasn't 'On Th Bus' so to speak but was very much part of the core group.
It was his Light Shows at all the early Trips Festivals and many Grateful Dead shows in their early years.
Kenn Babbs of the Merry Pranksters recenty posted up the below passage of text on Facebook which is a great story from back in the day:
13 September, 2020 at 11:32
Roy Sebern, the abstract expressionist painter who had painted the name, Further, on the bus had us over to his house one night to show off his latest artistic endeavor. An overhead projector, picked up at a school equipment sale sat on a table. We lounged on cushions, sipped drinks and smoked joints while Roy got organized. Paints and gels in small dishes and colored cellophane papers sat on the table next to the projector.
Roy turned off the light and turned on the projector. The wall filled with a square white image. He put a piece of cellophane on the projector and the wall turned bright yellow. He dribbled oils and gels on the cellophane, creating a swirling canvas. Changing cellophanes, using different oils and gels, he made flamboyant, exotic, ever-changing wall paintings.
Late in the night, after Roy wiped the projector glass clean, with white light filling the wall, a black beetle walked across the glass. It was gigantic, antennas waved like pliant spears, its beady eyes glowed. At the edge of the frame another beetle, even larger, jaws wide open, scuttled across the glass and clamped down on the first beetle. A tremendous thrashing ensued. The smaller beetle bent in two, reached back with its jaws and grabbed the big one in the mid section. Shells cracked, pieces flew.
Mouths open, eyes wide, we shouted, "You can do it, little guy," "That's it, gouge him in the eye," "No, no fair, no biting off his leg," "Oh, shit, that's his guts leaking out."
The smaller beetle fell limp. The bigger beetle ate it up.
Knowing there'd never be another show like that, we said goodnight to Roy and headed home. The light show, a staple of every rock and roll show to come, had been born.