Int he middle of writing the review and I've been asked several times for this info, so my apologies.
First the usual disclaimer ....
The graphs I use are generated using the Vibro Veritas coupler and ARTA software. Ken Ball (ALO/Campfire) graciously provided me with measurement data which I have used to recalibrate my Veritas so that it mimics an IEC 711 measurement standard (Ken uses two separate BK ear simulators, we measured the same set of IEMs, and I built my calibration curve from shared data). I do not claim that this data is 100% accurate, but it is very consistent, and is as close as I can get to the IEC 711 standard on my budget.
I do not claim that the measurements are in any way more accurate than anyone else's, but they have been proven to be consistent and I think they should be enough to give a reasonable idea of response - especially if you've followed any of my other reviews. When measuring I always use crystal foam tips (so medium bore opening) - and the reason I use them is for very consistent seal and placement depth in the coupler. I use the same amp (E11K) for all my measurements - and output is under 1 ohm.
OK - lets look at the graph
Black and blue are very close to identical, so are red and grey. This matched what I'm hearing too. If I use a red and a grey combo in either ear, I get pretty close to a perfect stereo match. Same with the blue and black. The approx 1 dB change is close enough that within a few minutes our brain compensates and the small differences tend to evaporate.
Now a few posts back someone talked about there being too much energy in the upper mid-range. And they were spot on (if talking about the blue and black filters). But its important to note that the upper mid-range is generally regarded to be talking about the area from 1k Hz to 5 kHz. Form 5-10 kHz is generally regarded as lower treble, and IMO the lower treble is pretty good (especially on the red and grey).
So for those wanting to balance the signature out a little - try this ......
For blue and black - try dropping your 30 Hz, 60 Hz and 125 Hz sliders down by about 2 dB AND your 2 kHz and 3Khz sliders by 4-6 dB
For red and grey - try dropping your 30 Hz, 60 Hz and 125 Hz sliders down by about 4 dB
The easiest trick though is to stick with red/grey and simply EQ the bass down a bit.