Redlined maps graded neighborhoods by coded race and decay categories for lending.

Evidence

Yellow areas are characterized by age, obsolescence, and change of style; expiring restrictions or lack of them; infiltration of a lower grade population; the presence of influences which increase sales resistance such as inadequate transportation, insufficient utilities, perhaps heavy tax burdens, poor maintenance of homes, etc. “Jerry” built areas are included, as well as neighborhoods lacking homogeneity. Generally, these areas have reached the transition period. Good mortgage lenders are more conservative in the Yellow areas and hold loan commitments under the lending ratio for the Green and Blue areas. … Red areas represent those neighborhoods in which the things that are now taking place in the Yellow neighborhoods have already happened. They are characterized by detrimental influences in a pronounced degree, undesirable population or infiltration of it. Low percentage of home ownership, very poor maintenance and often vandalism prevail. Unstable incomes of the people and difficult collections are usually prevalent. The areas are broader than the so-called slum districts. Some mortgage lenders may refuse to make loans in these neighborhoods and others will lend only on a conservative basis. — David Theo Goldberg, The Threat of Race, 371

Categorization

• DEFINE: Explains the formal security map classification system — yellow for transitional, red for deteriorated — that undergirded lending decisions.
• QUESTION: Worth checking: how exactly the color grading criteria conflated ‘undesirable population’ with physical deterioration — the category itself seems to smuggle race into an ostensibly objective index.