Color Button

Try this in your cf7 form :
[submit class:SendBtnColor “SEND”]

and add this in your css : .SendBtnColor {background:#ff00ff}

Check this bro

[submit class:mibutton2 “Download”]

<style>
.mibutton2:hover {
background-color: #008CBA;
color: white;
}
.mibutton2 {
background-color: white;
color: black;
border: 2px solid #008CBA;
padding: 16px 32px;
text-align: center;
text-decoration: none;
display: inline-block;
font-size: 16px;
margin: 4px 2px;
-webkit-transition-duration: 0.4s; /* Safari */
transition-duration: 0.4s;
cursor: pointer;

}

</style>

Source for more info and samples
http://www.w3schools.com/css/css3_buttons.asp

Try to add !important in your stylesheet :

form: [submit class:SendBtnColor “SEND”]

css: .SendBtnColor {background:#ff00ff!important}

That’s weird. Are you sure your css is included on your page?
Else, i’m sorry but I don’t know where it can come from :s

Don’t you have any place in your theme option to add custom css?
Usually in Appearance/Theme Options

Seems like it’s working.

.SendBtnColor {background:#ff00ff!important}
.SendBtnColor:hover {background:#ff00ff!important}

Also add the 2nd line.
Now just put the color you want

What about the result?
Don’t mind the /!\ on your screenshot, it just inform you you are using !important but you might need it to override your theme settings