I write my music by ear but can't get away from the same root-bass functional chords, for example Eb,G,Bb,D - DFAC and the like. I'll at least mix things up and put the 7th-tonic rub in the middle of the chord instead of on top, or find myself splitting 5ths doing root and 5th in the left hand and 3 and 7 in the right an octave up, a sus here and there but CAN'T seem to unlock my understanding of more "colored" (if you will) or nonfunctional chords and get into chromatic harmony and other techniques I hear in your writing. I'm not asking you to tell me "play these chords", but rather if you can suggest reading/watching something to expand my palate of harmony. (have basic diatonic theory under my belt)
first thing, think about the entire song not just the chords. if there's melody and lyrics in the song, do everything in service of that. and the other thing you might want to practice is playing all chords within a very small range. the order of notes you may have learned in school is kind of a myth. chords don't really belong in that order. i think if you play through some charts and deliberately play everything right around the middle C range, flipping as necessary to fit in that range, i think you will learn very quickly. also put the bass note an octave or 2 below, and if the chord has more then 4 notes then leave the bass note out of the right hand. i think you will learn things very quickly that way