SPO Modern Site Custom Theme

Question

Is it possible to create a custom theme in Modern sites and deploy it only at the site collection level? Just like we have option to create a site collection app catalog?

Answer 1

You can create a new theme if you are a SharePoint tenant administrator. Themes are applied to separate subsites, not to entire site collections. But you can apply a theme to an all individual subsites with a PowerShell.

Steps

• Open PowerShell ISE as an administrator

  

• Install PowerShell PnP Module by running the following command:

Install-Module SharePointPnPPowerShellOnline

• Connect to your target site collection:

$TargetSiteUrl = "https://tenant.sharepoint.com/sites/MySiteCollection"
Connect-PnPOnline -Url $TargetSiteUrl

• Open Site for Modern Theme geration > Apply Primary and secondary color of your choice.
• Click "Export Theme" > PowerShell tab and copy the code to your clipboard and paste to PowerShell into the $ThemeHash variable like so:

$themeHash = @{
"themePrimary" = "#0078d4";
"themeLighterAlt" = "#f3f9fd";
"themeLighter" = "#d0e7f8";
"themeLight" = "#a9d3f2";
"themeTertiary" = "#5ca9e5";
"themeSecondary" = "#1a86d9";
"themeDarkAlt" = "#006cbe";
"themeDark" = "#005ba1";
"themeDarker" = "#004377";
"neutralLighterAlt" = "#f8f8f8";
"neutralLighter" = "#f4f4f4";
"neutralLight" = "#eaeaea";
"neutralQuaternaryAlt" = "#dadada";
"neutralQuaternary" = "#d0d0d0";
"neutralTertiaryAlt" = "#c8c8c8";
"neutralTertiary" = "#bab8b7";
"neutralSecondary" = "#a3a2a0";
"neutralPrimaryAlt" = "#8d8b8a";
"neutralPrimary" = "#323130";
"neutralDark" = "#605e5d";
"black" = "#494847";
"white" = "#ffffff";
}

• Add theme to the tenant by running this code:

Add-PnPTenantTheme -Identity "Corporate Theme" -Palette $themeHash -IsInverted $false -Overwrite

• Apply theme to the target site:

# Apply theme to the root web of the site collection
Set-PnPWebTheme -Theme "Corporate Theme" -WebUrl $TargetSiteUrl

• Apply theme to all subsites recursively:

# Apply theme to all subsites recursively
Get-PnPSubWebs -Recurse | % {Set-PnPWebTheme -Theme "Corporate Theme" -Web $_}

Full Code

Install-Module SharePointPnPPowerShellOnline

$TargetSiteUrl = "https://tenant.sharepoint.com/sites/MySiteCollection"
Connect-PnPOnline -Url $TargetSiteUrl

# URL for generating themes: https://fabricweb.z5.web.core.windows.net/pr-deploy-site/refs/pull/8933/merge/theming-designer/index.html
$themeHash = @{
    "themePrimary" = "#0078d4";
    "themeLighterAlt" = "#f3f9fd";
    "themeLighter" = "#d0e7f8";
    "themeLight" = "#a9d3f2";
    "themeTertiary" = "#5ca9e5";
    "themeSecondary" = "#1a86d9";
    "themeDarkAlt" = "#006cbe";
    "themeDark" = "#005ba1";
    "themeDarker" = "#004377";
    "neutralLighterAlt" = "#f8f8f8";
    "neutralLighter" = "#f4f4f4";
    "neutralLight" = "#eaeaea";
    "neutralQuaternaryAlt" = "#dadada";
    "neutralQuaternary" = "#d0d0d0";
    "neutralTertiaryAlt" = "#c8c8c8";
    "neutralTertiary" = "#bab8b7";
    "neutralSecondary" = "#a3a2a0";
    "neutralPrimaryAlt" = "#8d8b8a";
    "neutralPrimary" = "#323130";
    "neutralDark" = "#605e5d";
    "black" = "#494847";
    "white" = "#ffffff";
}

Add-PnPTenantTheme -Identity "Corporate Theme" -Palette $themeHash -IsInverted $false -Overwrite

# Apply theme to the root web of the site collection
Set-PnPWebTheme -Theme "Corporate Theme" -WebUrl $TargetSiteUrl

# Apply theme to all subsites recursively
Get-PnPSubWebs -Recurse | % {Set-PnPWebTheme -Theme "Corporate Theme" -Web $_}