Update: I finally got what I wanted the way I wanted it. Thanks to the previous and the only answer and some enlightenment, I was able to improve upon the earlier code (shown on the question.) Anyways here's how I did it, hopefully this helps someone else in the future :D

@echo off
color 02
SETLOCAL EnableDelayedExpansion
for /F %%a in ('echo prompt $E ^| cmd') do set "ESC=%%a"
set "yellow=%ESC%[33m"
set "green=%ESC%[32m"
cls

:start
set det1=%random:~-1%
set det2=%random:~-1%
set dn=%random:~-1%
set randdet=0
if %det1% EQU %det2% SET /A randdet=%RANDOM% * (16 - 1 + 1) / 32768 + 1
set "cdn=%yellow%!random:~-1!%green%"

set rand11=%random:~-1%
set rand12=%random:~-1%
set rand13=%random:~-1%
set rand14=%random:~-1%
set rand21=%random:~-1%
set rand22=%random:~-1%
set rand23=%random:~-1%
set rand24=%random:~-1%
set rand31=%random:~-1%
set rand32=%random:~-1%
set rand33=%random:~-1%
set rand34=%random:~-1%
set rand41=%random:~-1%
set rand42=%random:~-1%
set rand43=%random:~-1%
set rand44=%random:~-1%

if %randdet% EQU 1 set rand11=%cdn%
if %randdet% EQU 2 set rand12=%cdn%
if %randdet% EQU 3 set rand13=%cdn%
if %randdet% EQU 4 set rand14=%cdn%
if %randdet% EQU 5 set rand21=%cdn%
if %randdet% EQU 6 set rand22=%cdn%
if %randdet% EQU 7 set rand23=%cdn%
if %randdet% EQU 8 set rand24=%cdn%
if %randdet% EQU 9 set rand31=%cdn%
if %randdet% EQU 10 set rand32=%cdn%
if %randdet% EQU 11 set rand33=%cdn%
if %randdet% EQU 12 set rand34=%cdn%
if %randdet% EQU 13 set rand41=%cdn%
if %randdet% EQU 14 set rand42=%cdn%
if %randdet% EQU 15 set rand43=%cdn%
if %randdet% EQU 16 set rand44=%cdn%

set set1=%rand11% %rand12% %rand13% %rand14%
set set2=%rand21% %rand22% %rand23% %rand24%
set set3=%rand31% %rand32% %rand33% %rand34%
set set4=%rand41% %rand42% %rand43% %rand44%

set randline=%set1%  %set2%  %set3%  %set4%
echo %randline%

goto start