@Anonymous user b90638
Allowing translate.googleapis.com and extensioncontent did the job for me, some other google stuff might be needed as well, but no need for google.com I think. Thanks for the hint anyway.


Example CSS for dark theme tooltip:

.TnITTtw-help-selected-wrap {
border: red !important;
}

.TnITTtw-has-bottom-arrow {
box-shadow: red !important;
}

.TnITTtw-help-inside-layout {
background: #272727 !important;
}

.TnITTtw-synonyms {
color: #cecece !important;
}

.TnITTtw-synonym {
color: #cecece !important;
}

.TnITTtw-unpinned-utils, .TnITTtw-utils {
border-bottom: 1px solid #7c231c !important;
background: #531713 !important;
}

.TnITTtw-util-button {
background-color: #bb352a !important;
}

.TnITTtw-original-variant {
color: #cecece !important;
}

.TnITTtw-main-variant {
color: #cecece !important;
}

.TnITTtw-top-arrow {
border-bottom-color: #531713 !important;
}

.TnITTtw-v-pos {
color: #777 !important;
border-top-color: #531713 !important;
}

.TnITTtw-v-item {
border-color: #531713 !important;
}

.TnITTtw-main-of-item {
color: #cecece !important;
}

.TnITTtw-dragBar {
background: #531713 !important;
}

.TnITTtw-icon, .TnITTtw-small-listen-icon {
background: url(moz-extension://*******************/resources/images/ui_elements/speaker_orig.png) center no-repeat !important;
background-size: 20px 20px !important;
}