Boxing important part of a frame

[Mehdi Haghgoo]

Hi
I was trying to signify an important part of a video for around 5 seconds by putting a color rectangle around it but I couldn't find any built-in effect to achieve this. Finally, I duplicated a cropped section of video just the size I wanted to signify, colorized it and put it over the normal track. This did the job but I was hoping there should already be an effect for this. 
Is there an effect to colorize/signify/amplify only a portion of a frame/track that I'm unaware of? 
Best regards
-mehdi
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