Ok on Boeing it is the following -

Pink - One high low chime (Cabin crew to Cabin crew phone call)
Pink - two high low chimes (Flight Deck)
Orange (Toilet call bell)
Blue (Passenger call bell)

On the widebody depending on which side blue light illuminates shows you which aisle the call bell is on.
Some airlines vary this and it is different on Airbus. The above is BA boeing.
Best way to remember it (How I was taught)....and very non P.C so cover your eyes...

Pink (Gay crew)
Orange (wee colour)
Blue ( B for bas*ards)

I did warn you!!