Any more pictures. Looks damp, so that’s making it look darker than life, plus colour is very saturated in the photo, so that’s distracting. It’s probably obvious but it’s not coming to me at the moment. 🧐
I don't think there are any spots on its throat, just wet feathers. Also even allowing for the colour saturation of the image it's got buff coloured sides and chest. The apparent light coloured outer tail feathers have also been pointed out. I agree on sylvia warbler, probably a female whitethroat.