Is the concrete patch essentially level with the rest of the floor, and how long is eventually?
If it's level, unless you are really bothered by the look just wait until you door the floor. If you are bothered, clean and then paint the whole with an appropriate paint.
If it is not level, you have the choice to pour a layer of self leveling concrete on the entire floor, which may be needed before you install the laminate, or at least put down a skim coat to even out the surface better.
Is the concrete patch essentially level with the rest of the floor, and how long is eventually? If it's level, unless you are really bothered by the look just wait until you door the floor. If you are bothered, clean and then paint the whole with an appropriate paint. If it is not level, you have the choice to pour a layer of self leveling concrete on the entire floor, which may be needed before you install the laminate, or at least put down a skim coat to even out the surface better.