Mouseover effect

Hello everyone,

I’m a newbie using Grav. Usally I play arround with wordpress, but Grav seems to be interesting too.
So my mainly question is, can I make an mouseover effect for a image? I mean the image is grey and after the mouseover the images turns into colorful logo.

Really this is just a CSS/HTML question and not Grav-specific. There are plenty of examples of this kind of effect out there: https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=image%20color%20mouse%20over%20effect