Ummm yeah, there is a way. The only thing that makes it seen through walls is the model (I believe), change the model by editing this line:
see_thru_walls_sprite = es.ServerVar("see_thru_walls_sprite", "effects/strider_bulge_dudv_dx60.vmt", "Special seen thru walls sprites")
To something like:
see_thru_walls_sprite = es.ServerVar("see_thru_walls_sprite", "sprites/purpleglow1.vmt", "Special seen thru walls sprites")
As I'm not exactly sure of the syntax or whatever of ESP effects using est.effect, I'm not sure exactly how to make it red, but I believe that would be achieved by editing some of the numbers toward the end of this line (whichever ones are RGB) to 255 0 0. I'm referring to the line of code I copied below.
#<x> <y> <z> <start radius> <end radius> <life> <width> <spread> <amplitude> <Red> <Green> <Blue> <Alpha> <speed>
#es.server.queuecmd('est_effect 10 %s 0 %s %s %s %s 30 50 0.1 50 0 0 255 100 100 255 0' % (userid, see_thru_walls_sprite, x, y, z + 50))
est.effect(11, userid, 0,see_thru_walls_sprite, x, y, z + 20, refresh_rate, 1, "%i"%alpha)
Hope the non-Python coder helped.