Not octaves. An octave is a doubling of frequency. When you go seven octaves below 'red' you are much, much lower than IR and when you go 7 octaves above blue you are way higher than UV.
Am I? 7 octaves above 400nm is 3-4nm, somewhere between extreme UV and x-ray. 7 octaves below 700nm is about 0.7mm - the end of IR and beginning of microwave spectrum. Unless I'm really missing something in my calculations.
