What I’m saying does not apply specifically to just these anons, it’s just these three were the latest ones. This is for anyone else who has asked something similar.
The new customise page sucks balls, looks ugly and most importantly previews don’t even work properly, however, IT IS NOT THE END OF THE WORLD. People saying they can’t change their theme, or it’s impossible to change their theme or they’re stuck with the theme they have because they can’t get rid of the current one are overreacting slightly. Again, I’m not saying you’re wrong or have no right to be angry, I’m not even saying the new customiser is easy to work with, because it’s not. Since they changed to the new page I’ve been swearing more then I have all of the last month combined. But with a little patience - ok, alot of patience, you can still do something as simple as change your theme. HTML is HTML, it hasn’t changed into some foreign ancient language, plus most of the time it’s nothing to do with the HTML and it’s just the preview looking wrong or tumblr lagging behind.
Mission #1: Change Your Theme
Ok, you want to change your theme, say I have this theme right now and I want to change to this one. Copy the codes and paste into the HTML section. The live preview is skewed but it’s not totally non-responsive, if you’ve changed the codes it will resemble something like the new theme so you at least know you’ve changed the codes. If the preview looks exactly the same when you click “Update Preview”, well you’re either doing something wrong or you have a total different bug that you need to speak to tumblr about. “Reset Defaults” and “Save”. At this stage I would recommend you not to make any personal customisations as we want to make sure the theme is installed properly first. As long as the codes don’t have any major errors, like posts missing or sidebars calculated wrong, you should have a new theme.
Mission #2: Reset Defaults
This is the main problem people are getting. Reset Defaults is an important part, especially if you want the original color scheme. I’ve already talked about it here and that method should work as a temporary solution.
Mission #3: Knowing What Your Theme Looks Like (Before You Save)
This one is impossible because like I’ve said multiple times the live preview is not a live preview, it is not how your blog will look, there is something wrong with it because there’s just something wrong with it. The only way you know what your blog actually looks like is to go to the blog itself and refresh the page. Sometimes you might need to refresh more than once because tumblr is also laggy.
If you’re not going to make any personal customizations, it then depends on your confidence in the theme maker because as long as you’ve copied the right code and reset defaults, whatever you saved should look exactly like the theme. All you’re doing is swapping a set of codes.
If you do plan on making some changes then I would suggest having a side blog. Do whatever you want there and once you’ve perfected it, copy/paste it over.
Mission #4: When Things Go Wrong
Just use Tumblr Recovery.