Lately I've noticed certain pieces of fanart being labeled as official artwork. I have posted some of them below to inform you that they are not official. Pictures with an asterisk (*) indicate that the picture is a fan-colored image that was originally black and white concept art.
Angela's Winx Blog does have some official Sophiex pictures here (Bloom, Stella, Flora, and Tecna) and here (Musa and Layla). Angela plans on cutting the Lovix pictures out of these magazine scans, so be on the look-out for those!
Regarding the fan-colored concept art, you can see the original art here and many fan-colored ones here on Analadygaga.