Thank you for your question about your blue spruce tree, Chris.  I'm not sure where you and your tree are (Northern or Southern hemisphere), so I don't know whether it's almost spring or almost fall where you are.  I can see some webs on the left picture, which might be a sign of spruce spider mites, which are described here.  Without knowing your season, I can't tell you which life stage the mite would be in now.

The yellowing of the needles can be a sign of several diseases, all detailed here.  To identify which it might be, you'll need to use a magnifying glass to look for fungal spores.  Alternatively, you can cut off a branch (with both yellowing and webs) and take it to your local agricultural college for identification.  I hope this proves helpful.  Good luck!

Thanks so much for your reply!
i am from Greece, and now we have February...
i will follow your advices...

Have a nice evening!

Regards,
Chris,
Athens

Good luck, Chris!