Can STR-430s replace STR-440s or be mixed?

[FunkyMonkey]

Probably a trivial question for this forum, but here goes.

I've literally just received my 2007 LSC loaded with STR-440s (color coded yellow). As a precaution I ordered a pair of spare power tubes from the shop and they were sent out with the amp and I was told they would check they match.

Problem is they have sent a pair of STR-430s (color coded green). So I have 2 questions:

1) Can the types be mixed (as long as the right sockets are swapped out to keep the pairs together) and does it effect the sound?

2) If Mesa amps are fixed bias, what is the color coding actually for and will it matter that the pairs are different?

Thanks and apologies if this is trivial!!

Duncan

 

[FunkyMonkey]

Thanks! I was struggling to find what I needed when there is so much of it on the site!