Edit woocommerce page colours using custom css

Hi there

I am using a siteorigin theme and would like to change the following colors on my woocommerce pages:

1. The color of the place order button and the proceed to checkout button. I have been able to change the main background color from blue to orange but there is still a slight blue border around the buttons that I wish to remove.

2. Two blue lines appear at the top of the checkout page: one at the top of a coupon box and one at the top of a returning customer box. I would like to change the colors of these lines and the small square logo type images beneath them.

Could anyone help me with some custom css. i would really appreciate it. Screenshots below:

https://www.dropbox.com/s/p9yqsva1tj52pc6/Screenshot%202017-06-09%2014.54.52.png?dl=0
https://www.dropbox.com/s/pifyvpkvw4giobw/Screenshot%202017-06-09%2014.54.27.png?dl=0
https://www.dropbox.com/s/0dv3q6ou01wwkk6/Screenshot%202017-06-09%2014.53.46.png?dl=0

Regards

Alex