Hi @RenoFun,
A warm welcome to the Bunnings Workshop community, it is fantastic to have you with us.
It would be hard to colour match exactly without knowing the exact product that was used originally, but it looks like a light grey silicone.
I'd suggest using a neutral cure, light grey silicone such as this Selleys Light Grey Silicone Sealant, or this Sika Light Grey NO49 Davco N Silicone.
Check out How To Silicone a Gap for some guidance on the application of your new silicone.
Jacob
