Oops. Okay ... go to your original post and click EDIT > FULL EDIT
Upload the "color" version.
Click on the MANAGE ATTACHMENTS menu.
Click the RED X on the attachment you don't want in your post.
Click the GREEN PLUS for the attachment you do want to show in your post.
You'll get a pop up window about deleting the one, click okay (or remove - can't remember the exact word) and the board software will remove the attachment, leaving - hopefully - the "color" version.
I apologize, I didn't see a difference between them (I do have my monitor set darkish), so I just removed one.