Hi, just for clarification, what was once called 'synspilus' is now 'melanurus (red form)' . The 'melanurus' pictures of the OP is the orange form. Actually, the orange form's coloration can be quite variable with orange through brown through yellow, depending on mood. Here's a couple of pics of my 'orange' and 'red' forms for comparison.
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'orange' form
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'red' form