FRA vs Headlights and Side Rods question

I was curious to know if anyone knows the rules for headlights on during the day, and for side rod painting.

I am pretty sure that headlights are supposed to be on at any time a locomotive is in motion. Is this a FRA law, or just common practice? If it is a law, when did this become manditory? I know that even in the 60's most D&RGW ng locos didnt have their lights on in daylight.

As for side rods, after talking to Earl this past weekend, I know these are not allowed to be painted (colored). Does anyone know when this took place? Does this include the entire set of rods (valve gear), or just the main and side rods? I have seen pics of engines with rods painted into the 40's.

Casey