hey @User I got it to work just fine with the below code. It changes the style of the button for the sign up, sign in, reset password (enter email form), reset password (submit new password form). The below is in the frontend code:

EmailPassword.init({
      signInAndUpFeature: {
        signUpForm: {
          style: {
            button: {
              backgroundColor: "#0B72B9",
              width: "30%",
              margin: "0 auto",
            }
          }
        },
        signInForm: {
          style: {
            button: {
              backgroundColor: "#0B72B9",
              width: "30%",
              margin: "0 auto",
            }
          }
        }
      },
      resetPasswordUsingTokenFeature: {
        enterEmailForm: {
          style: {
            button: {
              backgroundColor: "#0B72B9",
              width: "30%",
              margin: "0 auto",
            }
          }
        },
        submitNewPasswordForm: {
          style: {
            button: {
              backgroundColor: "#0B72B9",
              width: "30%",
              margin: "0 auto",
            }
          }
        }
      }
    }),