fix: revert text preformat HC colors

The real fix is to update index.html to use the new preformat-background
colors, but that's a larger change than we should take for endgame, so
this commit just reverts to the previous colors we had for the release

Author: joyceerhl

src/vs/platform/theme/common/colorRegistry.ts

@@ -227,7 +227,7 @@ export const selectionBackground = registerColor('selection.background', { light
 export const textSeparatorForeground = registerColor('textSeparator.foreground', { light: '#0000002e', dark: '#ffffff2e', hcDark: Color.black, hcLight: '#292929' }, nls.localize('textSeparatorForeground', "Color for text separators."));
 export const textLinkForeground = registerColor('textLink.foreground', { light: '#006AB1', dark: '#3794FF', hcDark: '#3794FF', hcLight: '#0F4A85' }, nls.localize('textLinkForeground', "Foreground color for links in text."));
 export const textLinkActiveForeground = registerColor('textLink.activeForeground', { light: '#006AB1', dark: '#3794FF', hcDark: '#3794FF', hcLight: '#0F4A85' }, nls.localize('textLinkActiveForeground', "Foreground color for links in text when clicked on and on mouse hover."));
-export const textPreformatForeground = registerColor('textPreformat.foreground', { light: '#A31515', dark: '#D7BA7D', hcDark: '#000000', hcLight: '#FFFFFF' }, nls.localize('textPreformatForeground', "Foreground color for preformatted text segments."));
+export const textPreformatForeground = registerColor('textPreformat.foreground', { light: '#A31515', dark: '#D7BA7D', hcDark: '#D7BA7D', hcLight: '#292929' }, nls.localize('textPreformatForeground', "Foreground color for preformatted text segments."));
 export const textPreformatBackground = registerColor('textPreformat.background', { light: '#0000001A', dark: '#FFFFFF1A', hcDark: '#FFFFFF', hcLight: '#09345f' }, nls.localize('textPreformatBackground', "Background color for preformatted text segments."));
 export const textBlockQuoteBackground = registerColor('textBlockQuote.background', { light: '#f2f2f2', dark: '#222222', hcDark: null, hcLight: '#F2F2F2' }, nls.localize('textBlockQuoteBackground', "Background color for block quotes in text."));
 export const textBlockQuoteBorder = registerColor('textBlockQuote.border', { light: '#007acc80', dark: '#007acc80', hcDark: Color.white, hcLight: '#292929' }, nls.localize('textBlockQuoteBorder', "Border color for block quotes in text."));