Yes, it should be color #12. But there is no hover color?

1. You need to change the Color #14.

More info here: 

https://wpforo.com/docs/root/forum-themes/theme-styles/

2. or use the following CSS code:

#wpforo #wpforo-wrap .wpf-button:hover {
  background: #4caf50 !important;
}

Don't forget to change the red marked color code before using.

Hi,

Can i use same code for my web site ?

hi boka003,

If you have exactly the same issue, yes, you can use the same code. It solved my issue. But you'll have to change the background color according to yours.

Mine are green: #649E2D and #4caf50 are different green.