Why is the signature built as a table instead of divs and CSS?
Because Outlook for Windows renders HTML mail with Microsoft Word's engine, not a browser engine. It ignores stylesheets, drops float and flexbox, and collapses margins unpredictably. A table with inline style attributes is the lowest common denominator that renders the same in Outlook, Gmail, Apple Mail, and mobile clients, which is why every serious email template still looks like it was written in 2005.
My logo does not show up in the recipient's inbox. What went wrong?
Two likely causes. First, most clients block remote images until the reader opts in, so the logo has not been loaded yet. Second, the image URL must be publicly reachable without a login: a link to a file in Google Drive, Dropbox, or an internal CDN behind auth will render as a broken image for everyone outside your network. Host it on a plain public URL, and make sure the signature still reads fine without it.
How do I install this in Gmail?
Open the live preview panel, select the rendered signature with your mouse, copy it, then paste it into Gmail's signature box under Settings, General. Gmail preserves the inline styles from a rich-text paste. Pasting the raw HTML source into that box would show the tags as text instead of rendering them.
Is my name, phone number, and email sent anywhere?
No. The HTML is built by a pure function running in your tab, and the preview is that same string rendered back into the page. Nothing is posted, and there is no account, so your contact details do not exist anywhere outside your browser once you close the tab.
What does the accent color actually change?
Two things: the 3-pixel vertical bar on the left of the signature block, and the link color for the email address and website. The name stays near-black and the title and company stay grey, so the accent is a small brand touch rather than a full theme.