Sorry no suggestions re the needles going brown, but am concerned about how near it is to the fence.Think about the width of a mature yew. Even if you cut off all the branches at the back so it doesn't knock the fence over it will eventually overhang the neighbouring garden by a long way. Even a yew hedge can end up several feet wide. I would move it while it is still relatively newly planted.

Hopefully you bought Taxus baccata fastigiata, given its proximity to a fence - there is a yellow leaved form, but if that's not what you bought and it should be dark green, there's definitely a problem of some sort. This sort of appearance is often caused by cultural/environmental conditions, and can be caused by lack of water - it may not show at all for some weeks following being kept short of water. Since you only planted it in spring this year, did you keep it well irrigated during hot, dry spells this year? The other common cause is waterlogging - this can be down to the type of soil, or more commonly, insufficient or poor preparation/cultivation prior to planting, especially in heavier soils.

Without further information, its impossible to say which of these might be the cause, or whether neither of them is.

they also go 'bronze' when too wet too. mine did and sadly I hadn't realised that the neighbours garden maintenance people had dug a channel to help drain their ground onto the drive way between us and a nursing home. that now runs into ours :o(

we are in 'consultation' with them regarding the drainage issues.