Based on body shape and size, this appears to be a nymph of an assassin bug (family: Reduviidae).
I originally was thinking some species of Zelus (see bottom of post), but the orange body and bold leg-striping makes me think this is instead an early instar nymph of some species of Pselliopus.

Credit: B. Newton (2004); Source: Univ of Kentucky
Pselliopus barberi (the orange assassin bug) is one option.
I'm on my way out the door, so I'll come back to this next week to see if a more specific species stands out...
Note: I was originally thinking the genus Zelus was a good place to start -- though native to South/Central America, about a half dozen species are found in the US. Zelus renardii (the leaf hopper assassin bug) is one such species that has an orange-bodied, black/white-striped legged instar. It's native to semi-arid and Mediterranean climates (both found in CA), and it's not too atypical to find them on crop plants even in suburban areas. [Source]. However, the leg striping just isn't predominant enough