I bought a cast iron skillet and after washing it and then heating it I got a color like rust I bought a cast iron skillet and after washing it and then heating it I got a color like rust from fire side

After washing by  Dishwashing soap I dry it by tissues, then heat it over a high temperature

Now I season it

Is healthy using it with this color ??!!

I have no experience dealing with this type of fryer


Now I season it but is healthy using it with this color
This has happened because you didn't dry it thoroughly enough. 

I would advise starting the seasoning process again. This is a good visual guide from Joshua Weissman: https://www.youtube.com/watch?v=PDTCgxvmShc