Multiple discolorations in newly poured concrete slab

[smokinjoe2017]

We undertook one of our first home improvement projects this past weekend and had our small, builder placed back patio slabs demo'ed and had 2 new, larger concrete slabs poured this past Saturday. It's now Wednesday and one of the slabs (the larger one) looks fine while the other, smaller slab (pictured) is showing various discolorations and surface differences.

The other slab and area outside of the box all look uniform; grey with white speckles (which we understand will fade and even over time).

The area of concern is in the boxed area, where there's areas of black discoloration in some parts, while another piece of this slab looks bleached white compared to all the rest of the concrete work. It also seems to have a different surface consistency than the rest of the concrete.

I've read about treatments that can help with discoloration, but since there seems to be various discolorations going on, not sure the right approach.

Given we're newies at concrete work and the contractor has been of little help, we're reading all sorts of information online. Did a search but didn't see anything that speaks to treating one area with multiple discolorations/surface variations going on.

Should this be treated or will it even out over time? If treated, what would be recommended; vinegar, muratic acid or a commercial treatment of some kind? Would it work for both the black spots and bleached looking area?

Many thanks to anyone that has advice or expertise they could share.

 

[Chris705]

Pretty sure the color will even out once it cures (28 days). It looks like the concrete is still damp from placing & ground moisture. Give it some time.

 

[Shootinok]

Curious if that white area was poured first, or last.
It looks to me like that area took its initial set differently than the rest. Could be a different truck, or if poured first was it setting up while the rest was being laid down? Was it a different truck?
My opinion is, that area took a different amount of finishing work, and it was dryer when they put the broom to it. Either way it should ultimately get much closer in color as it fully cures. Color is subjective, however, so your opinion of "matching" may not be the same as mine. It may never be the exact same, but it should even up.

Difficult to tell in a small pic, but it looks like the two sections are broomed in opposite directions.

 

[James-W]

I agree that once the concrete cures the discolored areas may clear up.

Welcome to the forum. When you have some time it would be beneficial to put your location under your name. Sometimes knowing where you are located makes a difference when you ask a question.

 

[LegacyIndustrial]

Agreed, may clear up. Welcome to the Wonderful World of Concrete!