Hey underdog_32,
add one of the following snippets of code to your Custom CSS field, under Form Options in Optin Forms.
If you’re using form 01:
#optinforms-form1 input[type="submit"]:hover{background:#222!important;}
If you’re using form 02:
#optinforms-form2 input[type="submit"]:hover{background:#222!important;}
If you’re using form 03:
#optinforms-form3 input[type="submit"]:hover{background:#222!important;}
If you’re using form 04:
#optinforms-form4 input[type="submit"]:hover{background:#222!important;}
If you’re using form 05:
#optinforms-form5 input[type="submit"]:hover{background:#222!important;}
Change the HEX value to the color of your choice 😉
You’re welcome, glad to be of help 🙂