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The Lesli gem offers a seamless customization experience through an initialization file. By editing this file, you can tailor colors to create a unique and personalized theme for your Rails application.

Logo customization

Customizing the logo with Lesli is straightforward. In your main Rails app, create a folder at ROR/assets/images/lesli/brand. Lesli will look for this folder and replace the default Lesli logos with your custom branding logos.

You can override all the logo branding within your app by adding the following files:

app-auth.svg -> Replaces the image at the top of the authentication forms.
app-icon.svg -> Default logo for mobile devices.
app-logo.svg -> Main image used for the header, emails, etc.
login-background.jpg -> Replaces to background image on the login page.

Color customization

Inside our initialization file, you'll find a dedicated section for customizing the color scheme. Simply edit the color values for various elements such as the primary color, sidebar, header, footer, background, and hover effects.

See the example below

Lesli.configure do |config|

    # Main color palette for Lesli
    config.theme = {
        color_primary: "#193d8d",
        color_sidebar: "#ffffff",
        color_header: "transparent",
        color_footer: "transparent",
        color_background: "#eef2f6",
        color_sidebar_hover: "#dee7ec"

This is going to modify the corresponding SASS variables in the Lesli core:

$primary (bulma) -> color_primary 
$lesli-color-primary -> color_primary 
$lesli-header-color -> color_header 
$lesli-footer-color -> color_footer 
$lesli-sidebar-color -> color_sidebar 
$lesli-sidebar-hover -> color_sidebar_hover 
$lesli-color-background -> color_background

Lesli provide the same color palette as CSS variables:

:root {
    --lesli-color-primary: var(--lesli-theme-color-primary, #{$lesli-color-primary});    
    --lesli-header-color: var(--lesli-theme-header-color, #{$lesli-header-color});
    --lesli-navbar-color: var(--lesli-theme-header-color, #{$lesli-navbar-color});    
    --lesli-footer-color: var(--lesli-theme-footer-color, #{$lesli-footer-color});
    --lesli-sidebar-color: var(--lesli-theme-sidebar-color, #{$lesli-sidebar-color});
    --lesli-logo-color: var(--lesli-theme-logo-color, #{$lesli-logo-color});
    --lesli-font-color: var(--lesli-theme-font-color, #{$lesli-font-color});

You can modify the CSS variables at runtime, so your users can modify the theme.

Bulma customization

You can customize bulma changing the value of the variables, see: