Especially with the amber-colored glass at the top of the window, orange and pink would be nice for this room.

I agree that you should take down the trellis but be aware that you'll probably need to extend your decking rail along that side in order to enclose the deck for building code purposes. If that's more of an expense than you're willing to incur right now, consider at least taking it down to the same height as the rest of your deck and putting a top railing across it. You could then put in some foundation plantings that would climb up and cover the fact that it runs in a different direction than the front of your deck. If I'm looking at it correctly, your gate gives you access to your front door from your drive way. Am I right? In that case, I think your gate should stay where it is. I agree with flair lighting that a new light is in order over your entry. If you like the idea of a motion light, they make decorative outdoor fixtures with motion lights built in. Your fence would definitely look nice painted a lighter color. Right now, as flair said, it's a bit unwelcoming. If you're painting your metal roof, take your house and trim colors from there to coordinate. You could definitely paint your scalloped trim a different color than the house. Matching it to whatever trim color you choose would look great. Do you use the steps from your deck to access your yard? If not, I would consider removing them and closing in that portion of the deck as well. If you do use them, I would add a hand rail for safety purposes. Congratulations on your new house and good luck with your project!

I was about to say grey until I read the last line. What about a light brown carpet?

I agree you probably need to centre the vanity and the cabinet on the wall or they could look a bit odd! You don't say why you don't want a space between the window and the vanity - just my opinion, but I would think 300mm could be quite useful for a bin, a clothes basket or box, or a small stool for putting clothes on? The only alternative to leaving a space, is to fill it with something as the response above suggested. To avoid it interfering with the window, you could make this something lower, so it sits level with the top of the vanity. This could be built in and the wall lining put over it to create a single "shelf" level with the underside of the vanity top, or if you can find some freestanding open shelving of the correct width, which could also be cut to the correct height, you could wedge that between the wall and the vanity side when fitting the vanity. Just bear in mind also, that you'll lose some of your towel hanging space if you put something too high in the space.