Yep...is true. Colt copied Ruger on that one. It wasn't until after the Lightweight came out that the Colt Scout was introduced, and it too came out with a silver colored aluminum cylinder frame.
The Colt Scout however can probably be considered the model that killed the Lightweight, 'course just the name Colt had something to do with that also. Colt went into a price war with Ruger's Lightweight (Colt won this round) trying to reclaim the glory days of their SA production that they'd lost when WWII came.
Ruger may have lost the battle, but Ruger won the war.
Chet15