Add color mode script runtime safeguard

Editor assessment

The subject states the addition: a runtime safeguard was added for the color mode script. The fix type matches defensive hardening, and the component is named, so the reader understands the protection target, though the specific failure being guarded — presumably a missing global at injection time — is left vague by the word safeguard. No scope is present, though the script is identified. The body repeats the headline and notes a changeset, which documents release bookkeeping. No footers appear. Understandable and adequately specific.