Small bird with Olive Breast?

Hello, I am new here and I have just taken up this exciting new hobby of bird watching.
I am trying to identify a little bird I spotted last week.
I observed a small bird plucking the fluff off my freshly laundered towels hanging on the clothes line.
I noticed it had an olive colour on its breast and a dark stripe going from the eye area down to the nape. The back and wings were brownish tones.
I would consider size and build to be between a wren and a house sparrow.

Thanks, ScarletRose.