✦ Starter Troubleshooting ✦
Throw it out. Don't try to save this one.
Pink, orange, or red streaks or patches in a starter signal bacterial contamination, and it's the one discoloration that's a hard stop. Unlike mold, it can appear without any fuzz, sometimes as a slick or a streak through the mixture.
This is not the same as a starter looking slightly tan or beige. Color from rye or whole wheat flour is normal. Pink and orange are not, and neither is anything that looks like a stain spreading through her.
Don't taste it to check. Don't scrape it off. Don't feed her and see if it clears.
Wash the jar thoroughly in hot soapy water, or start with a new one.
Why it happened. Usually a long stretch unfed, a warm room, or contamination from utensils. The same habits that prevent mold prevent this: clean tools, a wiped rim, and a regular feeding schedule.