Austria 20 Kreuzer 1818 Genuine And Counterfeit

I have a couple of other coins from other countries that has similar wear and the colour is different, does that mean that they are also fake and plated ?

I can contribute this Spain 1718 2 reales in rather poor condition. No longer in my collection. I never checked but assumed the underlying metal to be something like brass.

Hi Albert, this is the coin in question on the left, it has a slight reddish colouration on the lower relief areas. What do you think ?

It's not really that rare or ultra old, I think colloquially collectors call it "The Great Hall": https://www.NGCcoin.com/price-guide...duid-1309568

Oh, now I see it. First I thought China because no pic of the other side, so I began to find out what it is, edited out China and guessed a similar Japanese temple. Now I see it is Yunnan. The OP should have shown the other side to get a better reply.
The OP asked about color. Cameras, color settings, color calibration and lighting can make for too many variables affecting color so I can't comment on that.
The denticles appear to vanish on the right side so that doesn't look right.
If you could post a close image of the other side than is well in focus- that might help.
I do have some fake Yunnan 20 cent pieces, but not this particular one. Let's see a good pic of the other side.

Update: Now a good picture of the Obverse has been posted and I see that the coin should be in question. However, I can't say good or bad for certain by pictures in this case. If it was mine in my shop, I'd find out fairly quickly. I'd say what others have said and that is to presume it's not genuine, but then proceed to prove it's either good or bad. I do it by inspection and testing in the shop. Maybe I can add some suggestions: The silver fineness is not consistent and some provinces refused to accept them. Compare these measures: 5.3g, 1.25mm thick, 24mm diameter. Here are some differences among three varieties: The character Yin has one less stroke less at lower left, character Yin is diversified and the lower right of the building is deviating, characters at top and right in the inner ring vary in style, roof-riders slightly deviate in form. So for these reasons I'd be a poor one to say if it's good or bad. In closing, I'm ashamed I didn't see this as Yunnan at first. My excuse: its a one year modern type and I generally work with much older fakes.