Align portal with AIoD styles

As found out by Carolyn, some changes are needed to align with AIoD styles:

• aiexp.ai4europe.eu/css/ui-carosel.css, the color #1b033d needs to be replace with #003399 ( background-color:#1b033d; )
• aiexp.ai4europe.eu/css/home.css, for the font, #6822a1, this should be replaced with #0047BB ( .explore h6{text-align:center; color:#6822a1; margin: 5px 0 10px; font-size:18px; font-weight:normal;} )

to be done on the aiod branch