My designs tend t be deliberately unobtrusive and understated in the main, with bold titles and dividers to maintain clarity and contrast between areas of the page. Brighter green colours just make it look insipid, so I'm really stuck as to how to attack anything bright and airier.
My colour scheme was based off the original image AI used in the first one as a background (Motoko looking out over the city form the airport tower). The greens in that are deliberately kinda flat I think. It almost reminded me of the Matrix
Also, there are a lot of awkward limitations on the colour scheming in phpBB that make getting it perfect almost impossible.
I'll backup my first attempt and see if I can lighten it, maybe by using more white and greener shades.