Rainbow Yang-KY Announces Board's Election of New Chairman

1. Date of board resolution or change: 2026/06/22 2. Position type (Chairman or CEO): Chairman 3. Former incumbent's name: Kao Kuei-Chen 4. Former incumbent's resume: Chairman, Rainbow Development Technology Co., Ltd. 5. New appointee's name: Kao Kuei-Chen 6. New appointee's resume: Chairman, Rainbow Development Technology Co., Ltd. 7. Nature of change (resignation, removal, end of term, role adjustment, severance, retirement, death, or new appointment): End of term 8. Reason for change: Following a full board reshuffle, the new board elected the Chairman 9. Effective date of new appointment: 2026/06/22 10. Other matters to be disclosed (if applicable to public companies and qualifies as material information under Article 7-6 of the Enforcement Rules of the Securities and Exchange Act): None

Keywords: Material Information