Where you have the settings for how the media plan is displayed
https://rozpakui.crm-onebox.com/admin/modeview/roliki/issue-list-mode-mediaplan-... - you can make a setting so that one of the displayed fields ( e.g. Time) each unique value highlighted the time cell in a different color. That is, your cells with the value 01:00 will be highlighted in one color, 02:00 in another, etc.
You can - 6 hours of refinement to implement the functionality for you, and if you don't like it - another 1 hour to remove it.
This is the assessment of the above.