Can't escape backticks in code block containing in template literal

Based on this answer I wrapped my single-line backticks with double backticks and my multi-linke backticks with triple backticks:

:style="{'--overlay-color': ```rgba(${ bannerOverlayColor.red },    ${ bannerOverlayColor.green },    ${ bannerOverlayColor.blue }, 0.3)```,  height: ``${ bannerHeight }``,}"

Yet it doesn't seem to work. What am I doing wrong?

Demo