Button css

I have the following in the custom css file:

.sapMBtnInner {    background-color: brown !important;
 color: white !important;
}

The button displays the white color when the mouse hovers over the button and when the mouse does not hover over the button. However the button displays the brown background color when the mouse hovers over the button, but it does not display when the mouse does not hover over the button. 

How can I ensure the background colour is brown for both states? 

Design Studio 1.6 SP01

Theme: SAPUI5 m mode

Internet Explorer 11

Thanks in advance.