The yellow wall color isn't helping much unfortunately.

My husband unfortunately choose the yellow. I tried to incorporate the grey to tone it down. We are total opposites. I gave in since he has to live here.lol

Yeah yellow is not working for you at all... But I love where you're going with that shower curtain. Why not go with greys and whites in there. Here's a house article about transforming a bathroom from yellow to grey: http://houzz.com/ideabooks/7956692

You'll need to paint the walls (grey) and remove that band of tile. Update the faucets with something sleek and silver. Replace that yellow toilet seat. Replace the vanity mirror and put up more lighting. Hand the full-length mirror on wall and paint the frame black or white.

Utilize your vertical space by hanging a cabinet and a towel rod above the toilet. This will help to visually declutter. Move the air freshener and other things on toilet into a cabinet or under sink.

-- Your palette is right there in the tile band and you really cannot ignore it - it should be used or removed. The yellow is not helping and this needs to be explained to your hubby [ in the kindest possible way!]. Maybe he could paint a yellow wall somewhere else in your home?

Since your bathroom is small, choose the lightest color in the tile band and paint away. Simplify, simplify, simplify!

The clutter has to be reigned in by adding upper cabinets over the sink and toilet. Get the shallowest ones possible because all of those bathroom products are not chubby. Also, you can probably toss a few old products. Redo the under the sink space for more storage.

Find a good towel storage unit that might stand next to the toilet or one that you can install on the back of the door that has bars for towels - shown above. The crates shown below, stacked, is an economical storage unit. These could be painted to match the walls so they blend into the wall. Again, be careful not to 'show' towels that are not within your palette. That adds up to more clutter.

Replace the shower curtain with something simpler - the stripes are way too bold for this small space. Remove the loofas - not for public viewing - not decorative. Leave the shower curtain pulled to one side. This would almost double the width of your bathroom - just keep the tub sparkling clean.

I agree with tips from Sandy. You have two problems: colour doesn't work, fighting the tile & the shower curtain, and there is too much going on. If this is the only bathroom, need to take items off the wall & off the sink ledge, & back of toilet & find a good storage unit. Clutter reduces the size of a room.
In a small room, everything has to work together, to create flow - that isn't happening in yours, but it can.

If your husband wants the yellow to stay on walls, then work with that colour by changing shower curtain so it blends with the yellow.

Order a door from lowes that has a built in center mirror on the door. I did and my bathrooms look twice the size and its so functional.

Put up a large wall mounted medicine chest for more storage. There is a reasonable one in all mirror from Koher online at homedepot. (lighting would need to be moved above)

I would avoid too many storage units mounted on the walls because it may make the room feel closed in. How about putting one of those beautiful mirrored small chest of drawers (or a white one) next to the toilet Don't let any accessories be seen.

Put up artwork on toilet wall. Put up a double towel rod. Paint your brown vanity possibly.

I never manage to put all my ideas in one post... ;)

I just got to thinking...if hubby is sold on yellow you could still make it work by using it as pops of color instead of as the focus. Here are some ideas for some yellow pops. I wouldn't out more than 1 or 2 pops in the room sin it's so small- maybe let hubby pick which pieces of the room get to be yellow ;) my hubby LOVES making those decisions... Hehe.

Let us know what ur thinking. Are we getting it right or need to try a new direction? :)

If you can, mirror one of the walls in it's entirety "without a frame". That will make the room appear bigger.