[fschop]

I use mobilesheets to make my annotations in the music scores. I play the piano and often accompaniments. To avoid confusion with the (original) scores, I do avoid black and grey.
This is my style/colors for annotations:

• Red pen: handwritten annotations, like fingering, underlining, circling
  
• Green marker: emphasize or prioritize notes or melody lines, especially when it is not the top notes
  
• Blue stamp: stamps like sharp, flat, natural (as reminder), accents, dynamics (e.g. [i]f, ff, mf, p, pp[/i]) and other stamps, but also hairpins for crescendo/decrescendo
  
• Yellow marker, vertical stroke: page turn (*)
  
• Pink hairpins: slight accelerations / slowdowns like in rubato or for expression
  

(*) I use the tablet in landscape mode with 2 pages on screen. While reading the right page, I can turn the left page at the (yellow) page turn marker, and vice versa. This way, I can turn pages where my hands are free to tap the tablet. I don't use a pedal for page turns, because my feet get confused when using a pedal to a turn page.

What is your style and color for annotations?

I particular thing I like to know is how to annotation a note or chord that is slightly delayed, such a closing chord of a phrase or at the end of a movement.