adjust mid in color scale domain
adjust mid in color scale domain

dmadeka/bqplot,ChakriCherukuri/bqplot,bloomberg/bqplot,SylvainCorlay/bqplot,SylvainCorlay/bqplot,dmadeka/bqplot,ChakriCherukuri/bqplot,bloomberg/bqplot,SylvainCorlay/bqplot,ChakriCherukuri/bqplot,bloomberg/bqplot