"Video Sequencer" makes video dimmer I created animation and rendered al frames, than I create new file, go to Video Sequencer &gt; Sequencer, press shift + A and add all frames to render them into animation. After that I see, that original frames really more brighter than rendered video, so I want to keep the original brightness. Compositor is not used.
Earlier I did animation and I do not remember that I had problems.
The color management is set to filmic. This does not only effect your renderings, but also the VSE output. So you need to set the color management to for example sRGB

 Where it says filmic choose something else.