The generator matrix

 1  0  0  1  1  1  1  1  1  1  1  1  1  X  1 aX  1  1  1  1 (a+1)X  1  1  1  1  1  1  1  1  1  1  1  1 aX  X aX  1  1  1  1  1  1  1  1  1  1  1  1  1 aX  1  1  1  1  1 aX  1  1  1  1  1  X  0  1
 0  1  0 (a+1)X  X aX  1 (a+1)X+a a+1 (a+1)X+1 X+1 aX+1 X+a+1  1  a  1 (a+1)X+a X+a (a+1)X+a+1 aX+a+1  1  0 aX+a (a+1)X+1 X+a X+a+1 (a+1)X+a+1 aX+a+1 aX+a X+1 (a+1)X a+1 (a+1)X+1  0  1  1  X aX+a X+a+1 a+1 (a+1)X+a aX+1  1 (a+1)X+1 (a+1)X+a+1  a (a+1)X+a+1 (a+1)X+a  1  1 aX X+a  0  X  a (a+1)X X+a+1 (a+1)X aX X+1 (a+1)X+1 (a+1)X  1 (a+1)X
 0  0  1  1 (a+1)X+a (a+1)X+a+1 a+1 aX+a+1 X+a+1 X+a X+1 (a+1)X aX+a X+a+1  a (a+1)X+1 aX aX+1  0 X+1  a  X  1 aX+a  X (a+1)X+1 X+a+1 (a+1)X X+a  X (a+1)X+1  a a+1  1 (a+1)X (a+1)X+a X+a aX+a+1 aX (a+1)X+1  1 (a+1)X+a (a+1)X aX+1  a aX+1 aX+a  X aX+a  a X+1  0  1  0 aX+a  1  0  a  X  1 X+1  1 X+a X+a

generates a code of length 64 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 185.

Homogenous weight enumerator: w(x)=1x^0+528x^185+228x^186+360x^187+129x^188+720x^189+264x^190+132x^191+48x^192+492x^193+96x^194+120x^195+21x^196+180x^197+96x^198+48x^199+36x^200+228x^201+12x^202+96x^203+12x^204+60x^205+72x^206+12x^207+3x^208+96x^209+3x^212+3x^220

The gray image is a linear code over GF(4) with n=256, k=6 and d=185.
This code was found by Heurico 1.16 in 122 seconds.