The ps1 grey firmware look was there from the start, the paint splat looking one was around or just before the psone I believe.
I know the grey blocks was first as a friends launch day unit had it and so did my own, this was before the twin stick controller was made and released.
Just in case anyone did not know, the ps1 had a twin stick pad before the dual shock with rumble motors in it, you can tell the difference by weight and the analog sticks, the original non rumble had sticks which look more like the 360 controller and dip in.
I have one (dual analog) and you're making me feel old.