Question about triads in a scale... confused.

[Colorblind]

Hey everyone I'm really confused right now and hopefully someone with more music theory knowledge than myself can help!

Okay so i have a good idea on how basic music theory works, such as scales, major.. minor... and whatnot

but something that is really confusing me right now is when it comes to triads in a scale...
okay for example lets take the scale G#-minor
In the G# minor scale i am able to use the B Note, now with the B note i can create the triad B Major not only can i create that triad but all the notes used in that triad are apart of the G# scale.

okay so that being said, What if i want to use the triad Bm... but in the Bm triad not all the keys are apart of the scale... (B,D,F#) D is the key that is not on the scale...
so does this make using Bm incorrect, i mean i know music you have the ability to do what you want if it sounds good... but in music theory would that be incorrect? or is it okay since the root key is B?

[Euphorizer]

I'm not very good at music theory, but from what I have figured out on my own, just because a scale is in minor, that does not mean that all minor chords will fit in there. As you yourself mentioned, D is not part of the G# minor scale, then this means that a B minor chord will be dissonant. That does not mean that you can never use a Bm chord in that scale, but it will be classed as an accidental, which means that you have to pull it off right or else it will not sound good.

[Lehsyrus]

It fits because to note is following the scale. In Music Theory each scale depending on if it is Major or minor has a certain progression that is still in the key. However you can also borrow chords from parallel and relative keys and they will still work. Look up Roman Numeral Analysis of key signatures, it's pretty handy.

If you find the triad doesn't fit the octave, you can also invert it for a more fluid movement between the chords.