Invert dark theme detection logic
Invert dark theme detection logic

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