Difference between conventional Eye-diagram voltage plot and "Eye-density" plot in ADS Keysight Simulation
temperature view = RGB , Blue = least common ,  like a phosphor decay storage scope. But probably a colour histogram of all voltage samples for each sample of cycle time.

Your channel out/in = 0.7/2.0V is lossy and nothing much to say about this channel.

There is a conventional correlation between SNR and BER and eye pattern statistics.  It is useful to predict error rate and improve margin statistics if possible with a short term measure instead of longer term comparing data for errors.  

Symmetry, jitterRMS , width, height , &amp; overshoot are all factors to consider.