Black and white hover effect images

Hi!

I posted this on the WP Shows Posts forum, but I think it might be better here...

I used this CSS to make the pictures to create a black and white hover effect on the homepage:

img {
filter: grayscale(100%);
-webkit-filter: grayscale(100%);
}

img:hover {
filter: none;
-webkit-filter: grayscale(0);
}

It works fine, but now ALL images on the whole site are B/W on hover. But I just want this hover effect on the homepage only and not on the other pages. Would that be possible?

Thanks again for the great support!
Eva