Clear browser cache

When updating a theme it's a good practice to clean your browser cache.
A cache is an information technology for the temporary storage of web documents, such as HTML pages and images, to reduce server lag. Browsers tend to cache files in memory, so your browser may keep old files in memory instead of providing you with updated versions of the files. If you do not know how to clean your cache, please find more infos here.

Clear and deactivate cache plugins

When you update a theme please clear and deactivate possible cache plugins installed.
Caching plugins work is by saving the dynamically generated HTML files and serving them from the cache whenever a request is made, rather than loading all of the PHP scripts from WordPress. Cache plugins create a static version of your pages and files, if you update a theme and you have a cache plugin it's possible you continue to see the cached version of your pages and files and not the new versions.

Save Theme Options

If you updated the theme and your site appears wired, probably without color palettes, the problem may be caused by not saving Theme Options after the update. When you manually install a new version of the theme you need to save Theme Options in order to re-create the stylesheet files with your custom settings. Please make sure you have saved Theme Options after the update.

File Permissions

If saving Theme Options doesn't help resolve the issue, it may occur that your server has applied incorrect permissions that don't allow the dynamic stylesheets to be written. To check the possible problem open this link with your browser and replace the string "www.undsgn.com/uncode/..." with your site name:

www.undsgn.com/uncode/wp-content/themes/uncode/library/css/style-custom.css

Your test URL should look like this:

www.yoursite.com/wp-content/themes/uncode/library/css/style-custom.css

If opening this URL you display just the following script, it means your server is preventing proper write permissions for the stylesheet files:

/*---------------------- File created dynamically --------------------------*/

To solve the problem access your FTP, navigate to the following files and change the write permissions (official WordPress documentation). Once the correct permissions are applied, just save the Theme Options. You can also contact your host and ask for proper permissions on these files:

www.yoursite.com/wp-content/themes/uncode/library/css/style-custom.css
www.yoursite.com/wp-content/themes/uncode/core/assets/css/admin-custom.css

Max Input Vars & PHP version

In a few cases, Theme Options datas, responsible for the styles, may be lost. This unlucky scenario only happens if your installation is not compliant with the Max Input Vars and probably not compliant also with officially WordPress recommend PHP 7 version.

At the time of the update, the server performs several functions, a low value of Max Input Vars, or an old version of PHP may lead to lost of datas. Unfortunately, we cannot do anything beyond notifying you that your server has very low values in the System Status. The System Status is the first page you see after installing Uncode. Note that the required Max Input Vars 3000 and PHP 7 are common to most hosts.

To verify the possible problem please check if your custom options, such as color settings, are still present in the Theme Options panels. If you notice that the options have been deleted you can only retrieve them through a backup that you can generally request to your host.