Inheriting parent site Theme in sub-sites - SharePoint 2013

How to inherit parent site theme on subsites?

Theme Inheritance – Publishing Sites

Site Settings > Master Page, under the Theme section of that page check "Reset all subsites to inherit the theme of this site"

Theme Inheritance – Non-Publishing Sites

Open SharePoint Management Shell as Administrator and start next command:

$url = "http://your-site"

$site = Get-SPSite -Identity $url

Write-Host "RootWeb Theme: " site.RootWeb.ThemedCssFolderUrl

foreach ($web in $site.AllWebs) {

  Write-Host "Web Title: " $web.Title

  Write-Host "Web Theme: " $web.ThemedCssFolderUrl

  $web.ThemedCssFolderUrl = $site.RootWeb.ThemedCssFolderUrl

  $web.Update()

  $web.Dispose()

}

$site.Dispose();