To zoom, left click and drag a box around an area, click the "Zoom In" button that is available, then press Enter (if graph hasn't already zoomed).
There are no P/E entries in the database > 100 or < 0. When a bubble is white in the default configuration (with P/E determining coloration), that normally means it is > 100 or < than 0.
Think of the white colored stocks as "white hot".