The difference between blue top and brown top solenoids is their orifice I.D (blue tops have a larger opening). and internal windings/closing spring rate that’s it, oh, and PWM table control in firmware.
Blue top solenoid higher fluid flow results in higher pressure that produce shorter shift events during part throttle operation that gives more firm faster shifts part throttle than old obsolete brown tops, tcu tunes work for brown tops but performance won’t be at peak level compared to Blue Tops and shifts per gear might not feel exactly the same. The majority of 2005-2006 722.6 transmissions have blue-top solenoids stock, Most all V12 cars came stock with them 722.649 trans. Some older 03 04 cars had transmissions replaced due to radiator issues and got updated transmissions with blue-tops. When you change out the conductor plate is when you can see if you have blue or brown/black solenoid tops.
If you have brown tops my calibrations still work but won’t be the greatest as PWM tables are set for blue tops as most upgrade to blue tops anyways. For best performance is to upgrade them to blue tops. SLR tcu will still work with brown-tops but performance will be degraded and shifts might not be exactly the same until you upgrade.
All 722.6 Cars need blue top solenoids for the best results for any tcu tune.