Create and deliver custom Metadata fields for HTML5 Ads

Hey everybody,

every once in a while we have bookings that include a background color for the whole page. (See screenshot below. “Normal” background color would be white) For image-based ads, we could use the field “accompanied HTML” for these color values, but HTML5 ads do not have this option. Currently, we are hard-coding these color values into our website and change its background, if AdButlers API delivers an ad with a matching banner ID. See the following code-snippet for example:

if (state.banner_id === "123456789") {
   document.getElementById("___gatsby").style.backgroundColor = "#000000"

I propose a solution, where we could add our own data fields for ads/ad-types. Data added to those should be delivered alongside the Ad via API. For starters, just plain text fields without validation etc. would be more than sufficient!