Change Email Template Background

[Sheba]

Hello, using Magento 2.2.6.  I can't find the directory that stores email templates. 

1.  Which folder houses design/email/header_template?

2.  How do I change the blueish background for templates? please see below

3.  How do I change the inside white background? please see below

Thanks for your attention.

[syedhasan]

Hi @Sheba 

1.  Which folder houses design/email/header_template?

Ans: /vendor/magento/module-email/view/frontend/email/header.html

2.   How do I change the blueish background for templates? please see below

3.   How do I change the inside white background? please see below

Ans: /magento/theme-frontend-blank/web/css/email-inline.less

you can changes in these files for you want to ...  

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[Sheba]

Thanks for your response but I don't see any line in the files to make the changes needed.

[Patel_Chirag]

Basically, there is 3 way to style your email template.

1. Inline Styles
2. Non-inline Styles
3. Override Styles

If you open email template, for example /magento-email/view/frontend/email/header.html, you may notice the inlinecss directive in the next string:

Non-inline styles for emails come from global and template-specific styles, as described in the following sections.

Follow this link to style your email template.