last few days I've been makin/editing some icons and changing them and now most are done but Skype and Youtube app icons just wont change....I've tried .png and .svg but doesnt work...I managed to change utube icon once but wasnt happy with it and after that I havnt been able to change it..I even changed the icon in Blanco theme but still wont change..any1 got any idea what could be wrong?

Also I my emoticons won't work, I knew they might break when changing themes but I read that they would turn just to some orange icons but mine turns into white empty page icon, also did the fix but there still just white empty page icons, what could be wrong here?