Single color shirts are often required and purchased by various agencies, legal bodies and work forces alike - the reason being that they are very easy to match to pre-existing service and official clothes, such as jackets and blazers; and at the same time the material from which they are manufactured - 100% cotton - ensures both high comfort and durability of the shirt itself.
These will serve long and well.
Single color shirts look also great in suits when matched well color-wise. Do not hesitate to try one of these and up your suit game.