calandry on "Jetpack Subscription Styling"

I am trying to change the jetpack subscription style to match my theme and have been unable to do so. I know nothing of PHP and I'm still learning CSS. I've tried using this format found on another thread, but haven't been able to get it to work as of yet.

.jetpack_subscription_widget input[type="submit"] {
/* Your CSS changes */
}

I want the button to be the color #EA141F
with the word submit appearing #fff
and a hover color of #364956

my site is http://columbusgabuzz.com I am using a child theme and trying to add the changes in the style sheet of the child theme.