Are there more images with different filters available for the April 6 Hubble image of Jupiter? This recent HST image of Jupiter near opposition is described here and here and was made under HST proposal 14756. It was taken with WFC3/UVIS. It is made from three images using narrow-band filters at 395, 502, and 631 nanometers. 

I am wondering if there were additional images recorded with filters at other wavelengths. If so, how could I go about finding them?
As those observations are from only a few days ago, I think the data will still be embargoed, usually one year, until it's publicly available.

To confirm this, I've looked at the Hubble Legacy archive, where Hubble data is made publicly available. When you look there, the last public data for Jupiter is from February 2016.
Although I couldn't use the retrieved data from 2016, as it's not the FITS format, but it downloaded something.

So either you'll have to wait it seems, or you contact the project PI and ask nicely ;)

In the HST proposal page from the MAST archive (that links to the legacy archive) you see the photos they've taken listed, but the data is not available, I guess due to embargo.

Edit:
However I'm not sure if the legacy archive has all the data, as there's one dataset from 2011 with which I've worked that should be there, and I can't find it. Weird.