I just returned a demo set of Colorado to the dealer. I have my whole system wired with Cardas Golden Reference.
I tried them(Colorado)between the LP12/Linto and also between my Ayre C5xe-mp and my ARC LS26. On the TT they sounded very close in timbre and some passages were maybe even a little more analytical than the cardas. I noticed the biggest difference on the CDP and that is where I decided to take them back. They were in my opinion muting or dull by comparison to the cardas. I did a similar thread about a month ago here before I tried them, you wish to search for that one and see the responses I received. But in conclusion I will keep the Cardas GR's, howevere I wouldn't mind trying the Niagra or Blue Sky. And to address your question more directly, I have never felt the Cardas to be bright, they will bring out the upper range in detail, but in a natural timbre.
I tried them(Colorado)between the LP12/Linto and also between my Ayre C5xe-mp and my ARC LS26. On the TT they sounded very close in timbre and some passages were maybe even a little more analytical than the cardas. I noticed the biggest difference on the CDP and that is where I decided to take them back. They were in my opinion muting or dull by comparison to the cardas. I did a similar thread about a month ago here before I tried them, you wish to search for that one and see the responses I received. But in conclusion I will keep the Cardas GR's, howevere I wouldn't mind trying the Niagra or Blue Sky. And to address your question more directly, I have never felt the Cardas to be bright, they will bring out the upper range in detail, but in a natural timbre.