What a lovely kitchen. Looks really good quality. I wouldn’t paint the units, it’s a huge job unless you are getting a professional painter to do it. You could make a huge difference by just retiling in a more neutral finish and a new worktop. The Zelig tiles (last picture) have a lovely handmade look. Not sure if that would fit in with your budget. An oak worktop would look amazing as would a quartz worktop but they are pricey, however there are laminate lookalikes which are much more affordable. By having everything quite neutral, you can then go a bit brighter with your wall colour. Sage green always looks good with cream as does Oval Room Blue by F&B.

Paint the fascias a sage green. That colour works well with the worktop colour.

I’m with Sonia. For me the tiles date the kitchen and the worktops are probably showing their age. If you can afford to replace them it will transform the kitchen and might well cost the same as professionally refinishing the doors.

And I also agree that painting cabinets is best left to professionals but you could change the wall colour to make the room feel different.

If it were my room I would try to find a Quartz worktop (try to find a warm colour as very white could make the cabinets look old) and I might well have a worktop splashback instead of tiles.

And then you have a neutral kitchen and can apply almost any wall colour. Choosing this is easy- you either choose a colour consistent with other colour choices in the house or you pick a colour from the rug. I like Daisy suggestion of a soft green wall colour (but only if the blue tiles have been replaced.)

Thank you all for your suggestions. That explains why I’ve been struggling with current paint colours. I realise now that the tiles are dated, taking a photo really helps with that. Blue was a ‘ thing’ at the time. Painted shaker kitchens had just started to appear and this was the plainest I could get. Think I’ll also get rid of the decorative part of the cooker hood and the pine shelves- they certainly date me! The units were painted in situ and need redoing anyway but I’ve got a bathroom to do before anything major in the kitchen so if anyone has colour suggestions to go with the tiles and work top, I’d be grateful.

Removing the tiles and adding new is a pretty quick and easy job.

I agree with others that you have a great kitchen in a lovely light space. 

Your kitchen reminded me a bit of one I've read about on this interior designers blog. Not sure of what your style preferences might be but maybe some inspiration here 

https://blog.making-spaces.net/2019/09/08/the-victorian-cottage-devol-inspired-kitchen/