Keeping in the mood

I am wondering if anyone has any tips on how to keep a tune in a certain kind of mood? Either one of two thing happen to me at the moment, either my track will sound too dark and heavy or too happy, I’m trying to strike a nice balance inbetween that hits emotional tension and hold it.

So I guess I’m trying to find out how to do this? Is this purly down to scales and chords?

obviously chord progression and scales will play a huge part in this as much as the type of sound you choose to use but i would say the main part is your own personal mood. I find if I’m in an aggressive mood i write aggressive music, happy mood then more uplifting and so on