Have you tried this?
Stack two copies of the clip on V1 and V2
For the V2 clip apply a Gaussian Blur effect.
For the V2 clip, change the Blend mode to Lighten or another in that category.
Adjust to taste.
You might also want to put a vignette on the composite, so nest the clips and apply a vignette effect. Some techniques are here: https://library.creativecow.net/devis_andrew/Color-Correction-3_Vignette-Techniques/1
Unfortunately, you cannot have “twinkles” on the background alone unless you have shot the talent against a blue/green screen or you rotoscope (mask) the talent which is a tedious and lengthy process.
You can brighten up an area in a scene by first isolating the area with a track matte effect, applying a Color Correction Effect and then adjusting the Levels parameter to brighten just that area.
More on that here, Track Matte: https://help.adobe.com/en_US/premierepro/cs/using/WSD5DF3869-526C-4888-9F89-D37F5D8E325Aa.html
Fast Color Corrector: https://library.creativecow.net/devis_andrew/Color-Correction-2_Premiere-Pro/1
Kevin Monahan
Sr. Content and Community Lead
Adobe After Effects
Adobe Premiere Pro
Adobe Systems, Inc.
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