Yea I'm missing the permissions to do that in signatures.

Allow Basic BB Code
Yes
Allow Color BB Code
Yes
Allow Size BB Code
Yes
Allow Font BB Code
Yes
Allow Alignment BB Code
Yes
Allow List BB Code
Yes
Allow Link BB Code
Yes
Allow HTML
No
Allow Image BB Code
No
Allow Code BB Code
Yes
Allow PHP BB Code
Yes
Allow HTML BB Code
Yes
Allow Quote BB Code
Yes
Allow Smilies
Yes
Can Upload Images for Signature
No
Can Upload Animated GIF for Signature
No