We have just released the update where you can add an IMAGE banner to your client portals instead of just a color. First things first, the size for the image is of the proportions 1800 x 200.
You can set a general portal banner image for all portals OR you can override that and create banner images that are client specific.
To upload your general portal banner image, head to CURRENT BRAND SETTINGS and in BRANDING you can upload your portal banner image here:
Once uploaded, it looks like this:
Now, if you did not want a general one and want client specific ones, you can override that and head to the ADDRESS BOOK on the client's profile and upload their image:
Remember, client portals are CLIENT specific so if you have multiple jobs for the client, there is only one client portal / banner image for them :) This is why the click specific banners are set in the address book. You cannot set client specific banners within a job...it can only be done in the address book.
We have made it so that the banner images fit screens of all size and will resize to fit it!