A quick click of the tune button and the screen reverts to its normal blue. The top image is how it appears with the noise present. The bottom is how it appears after sa press of the turn button. Not real urgent since the fix is so simple but I would love to know the cause.
Those are real signals, so it looks like (literally) the waterfall is working as designed. Signals with a higher signal level will now up as contrasting colors on the waterfall. The greater the signal level, the higher the contrast. The background color is determined automatically by default, so the wider the panadapter, the greater the intensity range of the colors.
Yes, The bottom image is of real signals. The top, to my eye is nothing but rfi of some sort and no real signal at all. It is a click of the "tune" button that restores a normal screen. I don't know if the ATU button would do the same.