normalize-color accepts functional colors with surrounding junk

Description

@react-native/normalize-colors fully anchors hex matchers (^…$) but not rgb/rgba/hsl/hsla/hwb. Substring matches are therefore accepted:

normalizeColor('xxrgb(1, 2, 3)yy') // => 0x010203ff (unexpected)
normalizeColor('rgba(1,2,3,0.5)extra') // => non-null (unexpected)
normalizeColor(' #fff ') // => null (hex correctly rejects)

Steps to reproduce

1. Open the Snack: https://snack.expo.dev/rykV9Sq-NOSJg8KWXawiP
2. Look at rows for xxrgb(1, 2, 3)yy, rgb(1, 2, 3)yy, and rgba(1,2,3,0.5)extra
3. Observe non-null processColor values and painted swatches (bug). Spaced hex #fff correctly stays null.

React Native Version

main / latest (package @react-native/normalize-colors, used by processColor)

Affected Platforms

• Runtime - Android
• Runtime - iOS
• Runtime - Web
• Other (please specify): pure JS @react-native/normalize-colors

Output of npx @react-native-community/cli info

N/A — reproducible via Snack / unit package without a local app install.

Stacktrace or Logs

N/A (incorrect non-null return value, no crash)

MANDATORY Reproducer

https://snack.expo.dev/rykV9Sq-NOSJg8KWXawiP

Screenshots and Videos

N/A

Fix PR: https://github.com/facebook/react-native/pull/58496

Start with the functional color matchers in @react-native/normalize-colors and reproduce the listed rgb, rgba, and spaced-hex cases using the linked Snack. Done means inputs with surrounding junk return null while valid functional colors continue to produce non-null values; the issue also links fix PR #58496.