Colour works on the strand, above the skin, so it never reaches the follicle that decides whether hair grows. It does not cause pattern hair loss.
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Color doesn't reach the follicle. It works on the strand, above the skin, so it can't touch what decides whether hair grows. What bleach and repeated color genuinely do is weaken the strand until it snaps, and hair breaking mid length looks exactly like hair falling out. One is damage you can feel. The other starts underneath, where no bottle reaches.
What bleach and repeated colour genuinely do is weaken the strand until it snaps, and hair breaking mid-length looks very much like hair falling out. One is damage you can feel between your fingers; the other starts underneath, where no bottle reaches. A doctor can tell them apart quickly, and the treatment for each is completely different.