Note the wrong plastic color can be poured over the wrong brass core.
The yellow on the $1 chips were poured on the $2.50 cores by the manufacturing company, so they are genuine errors.
However, counterfeits can be made by pouring yellow on the $2.50 cores.
Can the green be melted off and yellow plastic be poured over the $2.50 cores?

Buyer beware.
Just saying.