The generator matrix

 1  0  0  1  1  1  1  1  1  1  1 2a+2  1  1  1  1  0  1  1 2a  1  1  1  2  1  0  1  1  1 2a+2  1  1  2  1  1  1  1  1  1 2a  1  1  1  1  1  1  1 2a+2  1  1  1  1  1  1 2a  2  1  1  1  1  1 2a+2 2a+2 2a  1  1  1  1  1  2 2a+2  1 2a  1  2  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  1  0  0  2 2a+2  1 3a+2 3a+3  1  a  1 2a+3 2a+3 3a+3 a+3  1 a+1  a  1 3a 2a 3a  1 2a  2 a+1 2a+1 a+3  1 a+3 2a+2  1 a+1 a+2 2a+3 a+1 2a+2 3a  1 a+2 2a+1  2 a+2  1 2a+1 3a+3 2a+2  2  3  3 a+1  0 3a+3  1  1 3a+2 3a+3  a  a 2a+2  1  1  1 3a a+2 3a+2 3a+2 3a+3  0  1  3  1  1  1 3a+2  0 3a+2 a+3 2a+1 a+2 a+1 2a+1 3a+3 2a+2 2a+2 3a+2  0 2a+1
 0  0  1  1 3a+2 3a+3  3 2a+3 2a+1 3a+3  0 2a+1 a+2  2 a+1  a  a 2a+2  a 3a+3 a+3 3a+1 3a+2 a+1 2a+2  1 2a+1  0 a+3 a+2  a a+2 2a+2 2a  a 3a+2 2a+3 a+2  3 a+1 2a  1 3a+3  2 2a+3 2a+2 a+1  1 3a+1 a+3 a+1 2a+2  0  0 2a  3  3 3a+2 2a 2a+3  3 3a  1  a a+3 2a+1 a+3  0 2a+2  1 a+2 a+2  a  1 a+1 3a+2 a+2 a+1 3a+1  1 3a+3  3 2a+2 3a+2 2a+3 3a  a 2a+3 a+1
 0  0  0 2a+2  0  0 2a+2 2a+2 2a+2  2 2a  2  0 2a  2  0 2a  0 2a+2 2a  0  2 2a  2 2a+2 2a+2 2a 2a+2 2a+2  0 2a 2a+2 2a 2a+2  2 2a+2  2 2a  2  0  0 2a 2a+2 2a+2  0  2  0 2a 2a 2a  0  2  2 2a  2  0  0  2  2 2a  2  2 2a 2a+2  2  2 2a 2a+2 2a  2 2a  2  0  0 2a 2a 2a+2  2  2 2a+2 2a+2 2a  0 2a 2a+2  2  2  0 2a+2

generates a code of length 89 over GR(16,4) who´s minimum homogenous weight is 255.

Homogenous weight enumerator: w(x)=1x^0+804x^255+411x^256+2616x^259+792x^260+2388x^263+969x^264+2076x^267+540x^268+1332x^271+582x^272+1404x^275+390x^276+936x^279+255x^280+576x^283+99x^284+156x^287+48x^288+6x^296+3x^300

The gray image is a code over GF(4) with n=356, k=7 and d=255.
This code was found by Heurico 1.16 in 1.72 seconds.