Has a Karcher just destroyed my patio?

[MPEJ]

My patio is made of the yellow tinged cheap stone effect concrete slabs. They've been getting a bit grim and mud tinged recently due to run off and foot traffic.
Today the other half with the best of intentions borrowed a Karcher and has 'cleaned' the slabs. They now are uniformly concrete grey and look like pumice, what I now assume to be a yellow exterior glaze has gone from them
Other than discolouration which means they no longer match the Portland stone borders is this a bad thing? Will the slabs need resealing are they now damaged or likely to suffer more damage? They look quite brittle and porous now.

 

[Brigadier]

Please post a photo

 

[JohnD]

You can use masonry paint on external slabs, though it will wear away and need periodic re-coating, depending on traffic wear, so once you start, you can never stop.

I think you will just have to get used to the concrete colour.

 

[r896neo]

It sounds like the slabs are total rubbish. Dye should be fully embedded and not a lick coat in the top 3mm.

A photo would be good and who made the slabs and how long have they been down.

As an aside the karcher did not ruin anything as it is not a sentient being. Unless you have the new karcher HAL 9000