Silicone, Caulk And Colour

[mrsparks]

Just had some anthracite coloured uPVC windows fitted. I'd specifically requested that the installers didn't use trim on the insides - I just don't like them. So it's my job to make good around the frames on the inside. I know that there's silicone (non-paintable), caulk (paintable), paintable silicone, hybrid polymers, etc etc. And then there's colour. So:

1. On the bathroom window, which is tiled all around, I'd already removed the grout that the tiler had used around the frame many years ago - because it had cracked and fallen out - and I replaced with white silicone sealant. That looked good against the old brown window frame. I'm minded to use anthracite silicone this time - not least because a white line of silicone would need to be pretty perfect against a grey frame otherwise it'll look horrendous. The gap is only a few mm so there won't need to be loads of silicone. Thoughts?

2. Same with our en-suite bathroom which has shower boards (or whatever they're called) on the walls. They were never sealed around the window, but I'm minded to do it this time. Again - grey silicone?

3. Windows in other rooms - I'm minded to caulk and paint right up to the frame. I'll mask to avoid getting any caulk/paint on the frame.

4. A couple of windows will have biggish gaps around and have been problematic in the past. I've filled and caulked but the caulk always cracks. I'm tempted to use foam, or backing rod, fill as best I can, and finish with paintable silicone against the frame (I already have some) - because these are the windows that take the brunt of the sun and are likely to expand/contract the most.

Any thoughts gratefully received.