Looks like you have it thought out. I would suggest picking your roof color before you pick your paint color. Paint color is much easier to change over the years. Personally, I would pick a very neutral shade such as grey or black (like you suggested). This way you have many other color options for the color of your home as time goes on. You can find a beige/grey to soften the red in your brick. Versus a cooler grey (Wow that looks really blue next to the top one- but when by themselves, they both look more grey) It will be nice to see how your roof impacts the look of your home over the course of the year and throughout the different seasons. I am not sure where you are located but a north facing home, in the northern US, a grey will take on more of those blue tones. Yes, I would make those attic vents blend in. I am not sure that I helped any. Good Luck!

I think you should lean towards a light color, actually a whitish in my opinion. I've attached a site that shows different paint colors on brick homes, it might help you decide. Your roof is dark and using a cream light color will bring more balance to the house as it will be more prominent. Brick houses painted

Post a picture of the house as a comment. What style is the house? Where is it located?

I think a blue gray would look good. I wouldn't go too dark. I would also paint the garage doors that color. The white is uninspiring. Your roof looks gray, so you have a lot of options like the green shown above. Yellow is one of my favorite colors, but the yellow you have is too assertive, so as you said, tone it down if you do yellow again.