What does the green mean?

[v0031]

For this first edition, teams did not have to qualify, but were invited as being considered a ‘strong team’. Uruguay was the first host country of the World Cup: it celebrated its hundredth anniversary and being twice winner of the Olympics, Uruguay was considered to be a ‘strong team’.

Uruguay's national day?

[Snowstalker Mk. II]

Uruguay became an independent country in 1830 and hosted the World Cup in 1930.

[H.E. VOLODYMYR ZELENKSYY]

An anniversary is when the date of an event is repeated the next year or several years later (in this case, 100 years later). The hosting of the Cup happened on the 100th anniversary of Uruguayan independence because it was 100 years later.

[v0031]

Thank you. And is 1830 the year it got indenpendent? I find it 1825.

[True Federalist (진정한 연방 주의자)]

Thank you. And is 1830 the year it got independent? I find it 1825.

Uruguay declared independence in 1825 from Brazil, was temporarily united with Argentina and regained full independence in 1830.