This is my first time ever opening Marketo, so I am coming into this program as a total novice with lots of experience with email building and markup. That being said, I am totally lost.
Earlier today we built out a template (Snow Bunny) for an email and when we did tests of the template alone, no content, in some browsers it showed up completely broken. Check out image1. With content, the tests got even weirder. The three articles were breaking into separate lines, and then the background colors got wild. See images 2 and 3.
We decided just to change templates, assuming there was a problem with one. Now, this new template we are using (i am unsure of which one my coworker is using) doesn't have any problems with lines breaking, but it does have that background color problem. See image 4. I should mention that for every email host program I have access to that our test program uses (Email on Acid), the same colors do not come up for me as they do in the test preview. That being said, we do not want to send anything out until we can be sure that this is going to run appropriately and as designed.
Are you using the starter templates from the Marketo Library or your own HTML code from your previous efforts and placing that into Marketo? Here's a link to the email documentation that might help out: Email Marketing - Marketo Docs - Product Docs
One issue that I've experienced with the default templates is that they were created/released before the "great shift" in 17q4 when google started reading @media queries. To the best of my knowledge, there hasn't been an internal effort there to re-create the templates. It might be best if you've got working code to add that in as your own template and use the Marketo Email Syntax to create editable areas (search: mktEditable) around the content you want to switch up.
To create a new template, you'll need a "container" and "mktEditable"-class elements for the 1.0 Editor, and "mktoText", "mktoImg", etc for Email 2.0 Email Template Syntax - Marketo Docs - Product Docs
You could check out knak.com for more modern templates, I believe they keep their templates updated so you may have more success on a quick-turnaround there.
Let me know if there's anything specific you've got questions about.