When posting photos, use the same method for each. If you enhance the obverse, do the same for the reverse. The color variations are due to your modifications.
I like to rely on the good old "Trust your gut feeling". Check the weight and dimensions, Numista is a good source. Hopefully you did not pay any huge price for it, so it will not be a big deal whether or not it is genuine. Then your only problem will be how to ethically dispose of it, if that be your choice.
I only payed £10 for the coin and the weight is spot on 25g and it is exactly 37mm so I suppose there's not other way to tell.
As many guys will tell you, go with your gut feeling. If you like the coin, then keep it. If not, then dump it. It is a beautiful design coin for sure.
This coin looks real to me. I have several. If you have access to an XRF gun you can check the silver content. There's a jewelry shop around the corner from me that has one and I get them to check any suspect coin for me. I generally pay from about $15.00 to $20.00 for any I buy, so you're on the good side of that. As coin_nut says "Big old Silver coin, What's not to love?". I agree.