I'm setting up a splash page for an AAA baseball team and they want the guest to see it. The changes they want to make seemed pretty simple, but I was having some issues making the things. So I got a friend involved who's more familiar with HTML. After you manipulated the page it did not come out the way we wanted. I'm sure there is something we doing wrong. Any help would be greatly appreciated. Below is what they wanted to do. I was able to add the text, but I couldn't get the colors to change or the font. Also couldn't get the connect button color changed did get the text on it to change. The image I could never get that to show up.
I would recommend building and hosting your own custom captive portal. You can do this for free and host it on GitHub Pages. Rather than read the documentation.meraki.com material, I would recommend developers.meraki.com for more information. Here are some example guides, step-by-step to build your own fully HTML capable splash page: