New landscaping with lots of flowering shrubs. Rhododendrons, azaleas, roses, and so on. A professional plan would be worth the money.

Are the turquoise roof parts made of copper with verdigris?

What leads you to think that it is ostentatious? What type of budget do you have? Are you looking to warm it up with a different color? More information would help us provide constructive ideas.

The porch roof is too high to offer any protection from rain. I agree that a one-story porch roof would be much better. The arched windows don’t add anything special to the exterior...particularly the dinky dormers.
***The landscape is the worst thing. Every plant is small, squared, green, boxy, low, boring! You need a variety of plants: flowering shrubs in natural forms, two or three trees (larger, boxed trees which will be professionally planted using equipment) placed so they will not touch the house when they reach a mature size of 25-30 feet, and low-level flowering bulbs or perennials to bring color to the ground. The trees need to be placed to compliment the house, not block it. A smaller- growing flowering or open-limbed tree could be placed in front of the house.
Hire a professional landscape company for the plan and execution.

Architecturally the two-story porch roof and random arched dormers are the issue. The dormers are harder to fix, so focus on the porch for now. Then invest in some landscaping.

For starters I would do the easy fixes first. I would get rid of the square bushes and plant rose bushes or anything colourful to draw your eye lower. Paint your door, possibly that teal colour you have above the posts. Add some drama to your stairs with pots of colourful flowers. The idea is to draw the eye lower. The house is beautiful, the dormers being arched really don’t suit the style but I think with good landscaping in front it will make them less visible.