more universal addition of colortables

[clintrowe]

I was successfully able to add a colortable in MetPy but when I change to a different directory, the added colortable is not available. Is there a way to add a colortable so that it will show up regardless of the directory I am working in?
I'm using this simple script (colortables.py) to show available colortables:

from metpy.plots import ctables
print(ctables.colortables.keys())
exit()

In the directory where I added the colortable, the results are:
(base) C:\python\gempak>python colortables.py
dict_keys(['Carbone42', 'Carbone42_r', 'ir_bd', 'ir_bd_r', 'ir_drgb', 'ir_drgb_r', 'ir_rgbv', 'ir_rgbv_r', 'ir_tpc', 'ir_tpc_r', 'ir_tv1', 'ir_tv1_r', 'NWS8bitVel', 'NWS8bitVel_r', 'NWSReflectivity', 'NWSReflectivity_r', 'NWSReflectivityExpanded', 'NWSReflectivityExpanded_r', 'NWSSpectrumWidth', 'NWSSpectrumWidth_r', 'NWSStormClearReflectivity', 'NWSStormClearReflectivity_r', 'NWSVelocity', 'NWSVelocity_r', 'precipitation', 'precipitation_r', 'rainbow', 'rainbow_r', 'WVCIMSS', 'WVCIMSS_r', 'wv_tpc', 'wv_tpc_r', 'visgray', 'visgray_r'])

If I go up one level and run the same script, I get:
(base) C:\python>python gempak\colortables.py
dict_keys(['Carbone42', 'Carbone42_r', 'ir_bd', 'ir_bd_r', 'ir_drgb', 'ir_drgb_r', 'ir_rgbv', 'ir_rgbv_r', 'ir_tpc', 'ir_tpc_r', 'ir_tv1', 'ir_tv1_r', 'NWS8bitVel', 'NWS8bitVel_r', 'NWSReflectivity', 'NWSReflectivity_r', 'NWSReflectivityExpanded', 'NWSReflectivityExpanded_r', 'NWSSpectrumWidth', 'NWSSpectrumWidth_r', 'NWSStormClearReflectivity', 'NWSStormClearReflectivity_r', 'NWSVelocity', 'NWSVelocity_r', 'precipitation', 'precipitation_r', 'rainbow', 'rainbow_r', 'WVCIMSS', 'WVCIMSS_r', 'wv_tpc', 'wv_tpc_r'])

Please note the availability of 'visgray' and 'visgray_r' in the first instance but not the second. How can I add a colortable so that is in the registry where ever I happen to be working across directories?