"Red and white are the colours of England's flag."
Translation:Coch a gwyn ydy lliw baner Lloegr.
It is just that Welsh tends to use the singular in this context whereas English uses the plural.
Lliw, although generally the singular noun 'colour/color' has the meaning of 'colours/colors' when applied to team and country flags or regimental 'colours/colors'.
Another translation of 'lliw' is 'colouring/coloring'; so the above sentence could also be translated as 'Red and white is the colouring of the English flag'
There is no yr/'r/y needed in this pattern - see the section Notes for an explanation and more examples.
This is not so much as matter of what the subject of the verb is, but one of emphasis. The normal word order in Welsh is to put the verb at the beginning of the sentence. In this case, though, the colours coch a gwyn are being emphasised since they are the main point of the sentence - to do that in Welsh they are put at the start of the sentence.
- Sioned ydw i - I'm Sioned
- Adeiladwr ydy Sioned, nid athro. - Sioned is a builder, not a teacher.
- Frangeg yw fy iaith gyntaf erbyn hyn - French is my first language now.