Regarding the color-developing sensitivity of the alkaline blue 6B indicator preparation?

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1. Regarding the determination of the acidity of light petroleum products by titration, has anyone encountered a situation where, after boiling 95% ethanol for 5 minutes and adding Basic Blue 6B, the solution remains red even without adding an ethanol solution of potassium hydroxide for neutralization? (What’s the reason?). 2. Regarding the indicator Basic Blue 6B, different manufacturers produce colors that vary. Previously we used a certain brand, and the color obtained was purple-blue; while using Comeo, the color that results is sky blue, and it’s difficult to distinguish the endpoint color (How to deal with the issue of poor sensitivity in color change?) ) 3. When preparing Basic Blue 6B in accordance with the standard GB/T258-2016, it is necessary to use an ethanol solution of potassium hydroxide to neutralize the boiled Basic Blue 6B indicator, until it turns red after the addition of 1–2 drops; it then turns blue again after cooling. But what if, even after adding several milliliters of this ethanol solution of potassium hydroxide, the color does not turn red? (How many milliliters does everyone add?) ）