VBA RBG - "Wrong number of arguments or invalid property argument" - vba

Question

I know there are other questions which deal with the "Wrong number of arguments or invalid property assignment", but none which deal with this error being generated on a basic line assigning an RGB colour to a cell interior.
This error is generating on line 6 of the below. I don't understand how this is possible, as RGB clearly has three arguments.
The only thing I can think of is that, earlier today, I wrote a macro in a different (now closed spreadsheet), where I used the initials "rgb" as a variant name. I know that, in R, it's possible to redefine a base function accidentally by replacing it with a UDF, and I'm wondering whether perhaps I've now unwittingly changed "rgb" to be something other than the function in the VBA base code. But that doesn't sound plausible - I've never heard of that happening in VBA, and it's more of a "for dummies" type language which I wouldn't have thought would give users that optionality.
EDIT Yes - this issue is resolved by changing the name of the macro, which is a stupid error. However, I would point out that this error is also happening in a different subroutine, which I have not named in such a stupid fashion. I will need to investigate why it's happening in that sub too.
Option Explicit
Sub RGB()
Dim wb As Workbook
Dim ws As Worksheet
Set wb = ThisWorkbook
Set ws = Sheets("Sheet1")
ws.Range("G20").Interior.Color = RGB(255, 51, 204)
End Sub

Answer 1

In case the comments haven't explained it fully.. you state in your question:
earlier today, I wrote a macro in a different (now closed
spreadsheet), where I used the initials "rgb" as a variant name.
However, in the example you provide, you've actually called the Subroutine you're calling RGB as well. This is the cause of the issue. Renaming it would fix it but while I'm here I can share with you some other points:
This would work:
Option Explicit
Sub Set_G20_RGB()
Dim wb As Workbook
Dim ws As Worksheet
Set wb = ThisWorkbook
Set ws = Sheets("Sheet1") ' should really be Set ws = wb.Sheets("Sheet1")
ws.Range("G20").Interior.Color = RGB(255, 51, 204)
End Sub
However, to make it a little more useful, you might want to use something like:
Option Explicit
Sub Set_RGB(clr_rng As Range, red_value As Integer, grn_value As Integer, blu_value As Integer)
clr_rng.Interior.Color = RGB(red_value, grn_value, blu_value)
End Sub
Which could be called like so:
Set_RGB ThisWorkbook.Sheets("Sheet1").Range("G20"), 255, 51, 204
or..
Dim wb As Workbook
Dim ws As Worksheet
Set wb = ThisWorkbook
Set ws = wb.Sheets("Sheet1")
Set_RGB ws.Range("G20"), 255, 51, 204