✅ ternary select between static classes

i have two static classes like this

public static class WhitePieces
{
    ...
}
public static class BlackPieces
{
    ...
}

public static class WhitePieces
{
    ...
}
public static class BlackPieces
{
    ...
}

and i'm trying to select between them like this

var pieceClass = sideAttacking == Colour.White ? WhitePieces : BlackPieces;

var pieceClass = sideAttacking == Colour.White ? WhitePieces : BlackPieces;

and i'm getting this error:

'WhitePieces' is a type, which is not valid in the given context

'WhitePieces' is a type, which is not valid in the given context

why is that?