Changing colour of the Mailpoet inscription form button

I have a issue with this theme. I used Mailpoet to create a mailing list inscription form. The button of this form is yellow. I need to change its colour and I don’t have any idea how to do it. The yellow colour is totally out of the palette of colours I chose for my website. I cannot understand why this button is yellow.
Here the link:
Thank you.

Hello there,

I hope you are doing well today.

There is a customization option built into the theme for this. Please go to Appearance > Customize > Colors >Accent Color and simply change the accent color which will also change the button colors.

If that does not work out, please contact us and we can provide some CSS code to make the change.

Best Regards,

If all else fails, insert the following code into your CSS plug-in or child theme:

To change the text color of the button:

input[type="submit"] {
	color: #HEX color here;

To change button color:

#comments #respond .comment-form #input-submit, input[type="submit"] {
	background-color: #HEX color here;

Hey there,
Hope you’re doing well today

I’m seeing where the button is now yellow. Did you manage to get the issue sorted?

Please let me know so that I may mark the ticket as resolved.

I look forward to your reply.

Best Regards,