This boxwood bush is bear over the winter, then starts with mostly red leaf buds and from mid-march to mid-april (picture attached), the leaves loose their read and become a bright matte green. I went to a local nursery and all of their boxwoods looked nothing like mine, and I would like to buy some boxwoods that match the ones I already have. Can you help me?

I think this is a barberry, not a boxwood - Does it have thorns?

Oh dear...Boxwood or Buxus are evergreen.
This means they have leaves all through the winter.
You shrub loses the leaves in the winter, so is therefore deciduous...which rules out Buxus completely.

Yes, it has thorns
It is not evergreen (so not boxwood)?
I looked up barberry and can't find a match.. this bush does not produce berries.
Can you tell me what type of barberry it might be???

I did some more digging, and I think it is Limoncello?

https://garden.org/plants/sear...

There are five pages for barberries list in the database here, you can look through those and compare. Limoncello does seem possible. but there are many kinds.