The design of new icons in comment threads while mousing over

Maybe when mousing over these 3 icons, we can have them has the background color?

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gitlab-foss#32959 (moved) New icons related to issue page. gitlab-foss#32894 (closed) [Meta] Create Uniquely 'GitLab' Icons

cc @sarrahvesselov @dimitrieh

mentioned in issue gitlab-foss#32959 (moved)

@hazelyang Would all the icons have a color (instead of plain black) on hover or is it just the comment thread icons?

added UX in GitLab FOSS label

perhaps off topic here: i do feel that the the pencil is to thin compared to the other icons

moved from gitlab-foss#33677 (moved)