Odd skin problem

Hello, everyone.
I have a strange problem on the forum where I'm one of the admins that I'm trying to solve for a few days now and have not found the source of it...
We have recently changed a Phpbb2 version skin with a chosen Invision version skin.
The previous, phpbb2 skin had certain changes, but I don't know what kind of and where, since I was not the one who made them, but I am the one who must undo them:
Some (not all) topics were set to have the ability to randomly select the font color and a certain font. I was unaware of these, especially the font setting, until the skin was changed, because the whole forum had the same font.
The problem is:
In certain topics the font is still the one from the previous phpbb2 skin and the font color is somehow still chosen randomly. Since the current skin's posts bacground is very-dark-grey, you can imagine the possibilty of reading a black colored font...
Is it possible that the changes on the phpbb2 skin were made somewhere in the templates and were automatically installed from the previous skin into the new one, since not every topic is "infected" with this problem..? How can I undo those settings, since the Invision version skins have no templates? If I have to set the previous skin back, where and what do I need to do to undo the problem settings?
I have seen the same invision skin we used on another forum and the difference is very obvious.
Thanks in advance for all your help if there is any...

Hello,

Please take a look at this topic https://help.forumotion.com/t13102-my-themes-are-changing-by-themselves