Make it 3 socket, force 3 blue with vorici. Then roll the 4th and 5th with vorici sockets to blue, then roll the 6th red.
At first i doubt you will get it with 76 chromatic rolls
But then its all about luck.
And it is possible using the vorici off color trick. It will be expensive.
https://www.youtube.com/watch?v=0kXPc8IomRIStart with 3 sockets (not with 2 as in the YouTube video)
Color them all blue (120 chromatics)
Start making the 4th socket using the trick
every try and undo will cost you 13 jewellers
Start making the 5th socket using the trick
every try and undo will cost you 80 jewellers
Keep the red socket for last will cost you 350 jewellers (if unlucky you get a blue or green and have to do it again :) )
Link it.
I make my Bronn's Lithe (evasion armour) with off color sockets every season this way.
And there is no difference by getting off color on strength based or evation based armours.