Re"Doyouhavesomeadvicesfor mixing electric guitar
Sound has always tend to be cold and I would give it a warmth and amplify the resonance of the strings.
you spoke about add oscillators to guitar.
The only way is to experiment.
What you call 'cold' I might describe as 'airy' and what you call 'warm' I might call 'muddy'.
What matters is that it pleases you and the only way to do that is to learn your own techniques for getting the sounds you like.
I might use compression, limiting, EQ, phasing, doubling, low-pass filtering, gating or distortion to get the guitar to sound like I want it to but there is no rule book and no way to accurately describe sounds in words.
The short answer is, I don't know without hearing it.