How can I add my own logo and name to the Silverstripe CMS 3.1? I found that in version 2.x you can do it with LeftAndMain, I tried this in 3.1, but without result.
I wouldn't replace the SilverStripe branding with your own. Its disrespectful taking free software that people have put hard work into and branding it as your own. If you have made serious modifications to the code 25% or more then I could sympathise a little that you'd want to include your brand in there.
>>I wouldn't replace the SilverStripe branding with your own. Its disrespectful taking free software that people have put hard work into and branding it as your own.
Whilst I understand your point (and it would seem I meet your requirement as well over the 50% of the code I install isn't silverstripe) - it does seem flawed as the largest portion of the framework in silverstripe isn't silverstripes work at al - jquery, js tree, tinymce, etc, etc - see the thirdparty folder - I don't see them "branded in the CMS".
Again with our code - tcpdf, jpgraph, phpexcel all heavily weight the code to open source... not to mention I do not include apache, mysql and php in the branding.
Even if you do not reconsider your position - I'd advise that someone asking how to do something that is well within the licensing agreement shouldn't be made to feel bad.
I'd lastly suggest it is for the clients own good often. Even when doing plain CMS websites I've know people who do not understand what they are doing thinking - hey this is all free why am I paying a developer - get in a right muddle when they try and do anything themselves - it actually would be amusing if not painful when they realise things are not magic.
Replacing the branding is totally acceptable (one of the reasons BSD > GPL!).
I started on the idea of making the CMS easily 'brandable' by specifying a CSS variables file but didn't get very far with it (see https://github.com/silverstripe/silverstripe-framework/blob/3.1/admin/scss/themes/_default.scss for the default scheme). So in the meantime you can just load a custom CSS file using LeftAndMain::require_css() and override any styles using normal CSS techniques.