Transparency (Object property vs RGB color "Background color none")

What is the difference between

Transparent unchecked

If the object property “Transparent” is unchecked, then

<code 4D>
OBJECT SET RGB COLOR(*;$object_name_t;Foreground color;Background color none)
</code 4D>

makes the object’s background appear transparent.

And subsequently calling:

<code 4D>
OBJECT SET RGB COLOR(*;$object_name_t;Foreground color;Background color)
</code 4D>

restores the object’s background color to white.

Transparent Check-marked

If the object property “Transparent” is check-marked, then the object’s background appears transparent.

Calling

<code 4D>
OBJECT SET RGB COLOR(*;$object_name_t;Foreground color;Background color)
</code 4D>

appears to have no effect: the object’s background remains Transparent.

Question

What is the difference between the object property “Transparent” and the RGB Color constant “Background color none”?

In particular, why doesn’t

<code 4D>
OBJECT SET RGB COLOR(*;$object_name_t;Foreground color;Background color)
</code 4D>

have the effect of unchecking the “Transparent” property?