Gleasonator: Remember that all colours are set in the CSS, so whatever template you choose for WordPress, as long as you duplicat ethe CSS into your phpBB styles, you can effectively set whatever colour schemes you want.
Neon_: Good idea,it should be relatively simple. I'd do this: grab the WordPress default template (or classic template), and delete all the CSS.
Then, when you turn on template integration (WordPress in a phpBB page), it will take on the prosilver style.
Of course, WordPress will have several elements that aren't styled explicitly in prosilver, so you could then do a bit of tweaking. You'd need to add the SPANS for rounded borders to the template, and use the .forabg / .forumbg backgrounds if you wanted. be careful of the sidebar(s) -- if you use "special" markup, you have to ensure that WordPress widgets will work with them. Note that the WordPress themes aren't parsed by the phpBB template system (phpBB header and footer are, of course, but the WordPress page in the middle isn't), so you can't use phpBB template tags in there.
Put the CSS tweaks to a separate CSS file, and hey presto, you have a prosilver theme for WordPress.
If you - or anyone make such a theme, I'll happily roll it into the mod and give credit where it is due
. I really wanted a WordPress subSilver theme for phpBB2, but I thought it was such a shame to replace WordPress' clean markup with tables!! A prosilver theme would be great though. If no-one else does it, I'll eventually have to do it myself so WP-United can compete with the prosilver-styled phpBB3 blog mods that will appear.