What does the orange engine light mean on ford focus 02 reg

It's an indicator warning you of emissions and/or engine control failure.

It's a check engine light, have it checked right away. If you take it to a Ford dealer, they can give you a very detailed diagnosis, however they also charge about 80 bucks just to do that. If you take it to an auto parts store (AutoZone, Advance Auto Parts, NAPA, etc.) they will often be able to check for free, but it won't be the most detailed solution.