Hi all. For my first tank i bought a Sherman Calliope. I have never build armor kit and i need some help. I have read tons of thread about coloring and weathering but i'm a little bit confused. I would like to color the Sherman in the right way: so i think i need OD as a primary color...but then? How to give some nice effect to the model? I know is a broad question...but i need advices to make some trials. Thanks

I think you have asked a broad question . . . and there are plenty of threads on this site on this subject, and yet A) it's not too good that someone doesn't get a reply to this type of question and B) I totally understand why someone would still be confused having read practically all there is to read. I must say that even some features that have been written are not exactly easy to follow. You should however try this thread:
Finishing and Weathering Sequence

This at least gives some pointers and things to try out, and that is I think what you'll need to do. Accept that it is a learning process for one thing, and don't be disappointed if it doesn't turn out like some medal winning model on the first attempt.

My first advice would always be to make sure you use a white or grey primer to start and then on top of that make your base colour coat a bit lighter than you want the final finish to be, and keep it fairly thin. Beyond that is a world of experimentation . . . but have a go at some of the techniques on that thread.