How did you manage to miss a funeral? Especially as it was the reason you came?

Coincidently I'm at a funeral on Monday but all I have is my aforementioned light grey Primark suit. My girlfriend reckons it's not appropriate for a funeral but it's the only suit I own. Would it be rude not to wear a black suit?

The funeral in question is for my Grandad's brother. I didn't know him all that well but I wouldn't want to look disrespectful to my Grandad by wearing a grey suit