regarding charting multiple currencies on same chart, possibly with additional visual cues

- am interested in understanding how i might attempt to produce a live chart that concurrently displays multiple pairs (on relative scale)

another additional feature would signal trend divergence, such as: if gbp/jpy tick +.005% and usd/jpy tick +.001% and eur/jpy + .002% = "wash" [thus pair displays blue] ...etc.

but, if they significantly diverged, the pairs could display red or green or whatever.

thoughts?