How Do i solve these problems

Hey i have recently purchased a domain and installed wordpress i’m kind of new to all of this and came across a few problems. How do i move these pictures so that there is space inbetween them. https://s32.postimg.org/q8zzs3cs5/Naamloos.png

I would also like to know how i can change the picture when i hover over them. For example they are grey and when i hover over them the image changes and it now has color. I can’t do it with html and would like to know how to do it with css here is the link to my site Pokemasterboost.com and here is the code

Html
<i class="pixeden" style="background:url(http://pokemasterboost.com/wp-content/uploads/2016/08/luel.png) no-repeat center;width:100%; height:100%;"></i>

Css

element.style {
    background: url(http://pokemasterboost.com/wp-content/uploads/2016/08/luel.png) no-repeat center;
    width: 100%;
    height: 100%;

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