And if the tip of the swab changes to a pink or red color, it indicates the presence of lead.

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The alerts are color-coded: Blazing red indicates high risk.

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The pendant's bright gold color, even where it melted, indicates that it was made from high-carat gold, he said.

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When he got to the color, the blue on blue night scene set the stage and the slash of candle light through the window indicates that there are secrets to be had here.

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