Bria SolidColor Background Video

You have footage of a person or product on a messy background and you want it on a clean solid color - for a thumbnail, a catalog shot, a synthetic backdrop, or as a pre-composite step. Locally, that's a per-frame background-removal pass (hair, motion blur, and semi-transparency all make it miserable) followed by a color fill, and "temporal consistency" is where video cuts to black. Bria SolidColor Background Video does the whole thing as one hosted API call: it removes the background across the clip and drops in a flat color of your choosing. That's it. Your GPU never wakes up.

It's the simplest node in Bria's video family, and the most direct. The pack's other video nodes are two-step affairs - mask, then edit. This one is single-step: video in, color-replaced video out. Under the hood it hits the same endpoint as the remove-background node (/v2/video/edit/remove_background), with background_color as the differentiator - "Transparent" just means remove-and-leave-empty instead of fill.

What you set

• api_key - required. The prefilled BRIA_API_TOKEN placeholder gets rejected with "Please insert a valid API key."
• video_url - required. Hosted http(s) URL or local path (tooltip: "URL of video to process (provide either frames or video_url)"). Local files auto-upload to Bria's S3, so LoadVideoFramesNode chains straight in.
• background_color - the picker: Transparent, Black, White, Gray, Red, Green, Blue, Yellow, Cyan, Magenta, Orange. Default is Transparent.
• output_container_and_codec - and here's the trap hiding in plain sight: the default for this node is webm_vp9, not mp4_h264 like the others. That's deliberate. MP4 (h264/h265) cannot store alpha - pick mp4_h264 with Transparent selected and your transparency silently dies. If you chose Transparent, keep webm_vp9 (or mov_proresks for an NLE pipeline). The minute you pick a real color, mp4_h264 is fine and universally playable.
• preserve_audio - default true.

The single output is result_video_url - a STRING URL to the finished clip. Preview it with the pack's PreviewVideoURLNode; it's not a video tensor, so you can't chain it into arbitrary local video nodes.

Installing

Same drill as every node in this pack. ComfyUI Manager → search "BRIA API", or:

cd path_to_comfyui/custom_nodes
git clone https://github.com/Bria-AI/ComfyUI-BRIA-API

Restart, paste your token from platform.bria.ai. No models, no heavy deps - just requests and the standard ComfyUI stack. Mechanically it's async: POST, poll a status URL every 5 seconds (up to an hour), return the result when the job completes. Long videos spend a while in "waiting"; the console prints poll status as it goes.

Where it bites

The webm_vp9 vs Transparent coupling is the one that actually burns people - you'll see it in every "why is my transparent video black" thread, and it's not a Bria quirk, it's how containers work. Transparent needs alpha, alpha lives in VP9/ProRes, not h264. Remember it once and you're fine.

The bigger, softer issue is background-removal quality on video. The KB's background-removal essay is blunt that even the best segmentation models struggle with flyaway hair and semi-transparent material - and that's on stills, where you have one chance to get the edge right. On video you get the same struggle multiplied by every frame, plus motion. Fast-moving subjects, fine hair, and glass will produce a shakier cut than you're picturing. It's hosted and paid per request, so a good test is: run one short clip, preview it, decide if the edge quality meets the bar before you commit the whole roll.

And as with all the video nodes, the output URL expires - download what you need while it's live. Verdict: it's the fastest road from "messy footage" to "clean background" this side of doing it by hand, and for product work on a deadline it earns its fee. Just respect the VP9 rule and check the edges before you send it to the client.