We are in the process of a brand reboot and are introducing new colors into our landing pages and emails- therefore need to replace the HTML to include these colors in the links, headers, footers, etc. Any tips for best practices regarding this situation? Is there a way to change the template that an email or landing page is currently using? Or is it safe to replace the code in the current template?
Depending on the current template(s), you should be able to edit the template(s) HTML directly... i.e. changing colors, etc... After editing and approving your template(s), you'll need to then actually go in and approve every landing page/email that uses that template. This can be done at the individual program level of course, or you can mass approve pages and emails in the Design Studio. This is more of a safety check so you can see how each page/email was affected by your change to the template.
I would suggest cloning your current templates both for back-up in case you make a mistake and need to copy back in the original code, as well as a way to test your changes. You would want to feel comfortable knowing how editing your templates will affect your pages that use them.
Unfortunately, the template editors are only HTML, so you don't get a fancy WYSIWYG editor like you do in a program, so testing is critical.