A thumbnail system for the whole channel

You are a brand designer for channels. You balance two opposing needs: recognisable at a glance, and not so uniform that a viewer cannot tell two videos apart.

MY CHANNEL
Niche: [NICHE]
What my thumbnails look like now: [DESCRIBE THEM]
My content pillars: [YOUR FORMATS]
Can I appear on camera: [YES / NO]
Design skill and tools: [WHAT YOU CAN DO]
Audience: [AUDIENCE]

HOW TO DO THIS
1. Define what stays FIXED across every thumbnail. Two or three elements, no more: a colour, a text position, a border, a typeface. These are what make the channel recognisable.

2. Define what VARIES, and by what rule. This is what stops the set looking like one video uploaded repeatedly.

3. Give me a per-pillar variation: each content pillar should be recognisable as its own kind within the channel style. Say how.

4. Specify the TEXT RULE: how many words, where they sit, what size relative to the frame, and when there should be none at all.

5. Specify the CONTRAST RULE: what makes these stand out against the feed my audience actually scrolls — which in most niches is a wall of very similar-looking thumbnails.

6. Then a CHECKLIST I can run on a finished thumbnail in ten seconds, so the system survives contact with a deadline. Six items maximum.

Keep the whole system within the design skill and tools I described. A system I cannot execute is not a system.

RULES
- Two or three fixed elements. More than that and every video looks identical.
- Everything must be doable with the tools I named.
- Do not specify exact hex colours or fonts you cannot verify are available to me; describe the role and give options.

RULES THAT ARE NOT NEGOTIABLE
- Every claim in the title and thumbnail must be delivered in the video. Metadata that promises more than the video contains is what YouTube's spam policy calls deceptive, and the algorithmic cost arrives long before any manual review: the click happens, the viewer leaves, and the video stops being shown.
- No fabricated numbers, statistics, dates, studies or quotes. If a figure would strengthen it, write [CHECK: what to verify] and let me fill it in.
- Nothing that states or implies a guaranteed outcome — earnings, results, cures, or "you will definitely".
- No medical, legal or financial instruction presented as advice. Information, framed as information.
- Nothing sexualised, shocking-for-its-own-sake, or built on someone else's misfortune.
- No keyword stuffing, no tag lists unrelated to the video, no repeating a phrase to game search.

GIVE ME
FIXED — the two or three constants.
VARIES — what changes and by what rule.
PER PILLAR — how each format reads differently.
TEXT RULE and CONTRAST RULE.
TEN-SECOND CHECKLIST — six items.

BEFORE YOU ANSWER
Read your draft once and fix it:
- Would a person who knows this subject find anything here obvious or padded? Cut it.
- Is every specific claim something the video can actually deliver?
- Did any banned phrase survive? Replace it.
- Are the sentences varied in length, or do they all run the same? Fix the rhythm.
Then give me the final version only. No preamble, no explanation of what you did.