litte paint over, i dont have much exp with lighting such scenes so u might wanna ask Erik cuz hes better with the lightzzz
but the main thing is that u lack is focus. u use a nice rainbow range of colors (which is possible but they have to work together, yours do not)but i think u dont know why u are placing them. so do research look at pictures that express the same mood u want to achieve. studie them and then apply what uve learned there to your painting.
or keep them next to your painting so u can look at it