@Neil408
Hello from over in Auckland, New Zealand where the shade of blue in your bathroom is still found in homes from time to time.
We used to have an original bathroom in the 1900's home our parents had with that same blue tone - the second image you have placed online.
It contrasts the green grass, forest & nature outside, provides a sense of relaxation & calm & makes one feel like it's a sunny summers day in the winter & on dull days.
Those aspects all help create who we are and what mood we are in.
Bathrooms tend to be where we start and finish our day.
With your home been created in 1700's circa please keep it the colour it tis.
What colour linen do you provide as there isn't any in the photograph?
The whole tone of a room can change in an instance with accessories like linen, artworks, paintings.
Is it a bathroom you also share with your guests?
Or exclusively for your guests?
Do you have any images , or can you find any of the original home as it was in the 1700's?
If so perhaps print some off & put one on the wall in the bathroom or other rooms.
There's nothing lost in having a play around with Artworks in a room to alter the mood of it.
Most of all, Remember, it's the person inside a home that's most important not how it looks or what we have inside....