Date Picker: Focus on the Calendar Icon fails to meet minimum required color contrast of 3:1 for visual focus outlines.

[achuth2912]

OpenUI5 version: 1.127.0

Browser/version (+device/version): Google Chrome 128.0.6613.138

Any other tested browsers/devices(OK/FAIL):

URL (minimal example if possible): https://ui5.sap.com/#/entity/sap.m.DatePicker/sample/sap.m.sample.DatePicker

User/password (if required and possible - do not post any confidential information here):

Steps to reproduce the problem:

1. Focus on the DatePicker Icon

What is the expected result? Focus outline around all focusable elements must be distinct and pass a minimum of 3:1 Color contrast against its background.

What happens instead? Color contrast fails with 1.6:1 ratio

Any other information? (attach screenshot if possible)