Color change doesn't affect footer

I have changed my imbalance 2 footer by using CSS and it all worked fine. I've been using it for a while
and now I want to change the color of the footer. I've tried to change the color of the footer using the following code:
.footer {
    background-color: #f5f5f5;
    color: #000;
}

But it doesn't work. I've