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

generates a code of length 90 over GR(16,4) who´s minimum homogenous weight is 258.

Homogenous weight enumerator: w(x)=1x^0+624x^258+816x^259+153x^260+1656x^262+1260x^263+225x^264+1944x^266+1116x^267+177x^268+1680x^270+936x^271+141x^272+1284x^274+708x^275+159x^276+900x^278+540x^279+102x^280+636x^282+408x^283+18x^284+324x^286+276x^287+24x^288+168x^290+72x^291+18x^292+12x^295+3x^296+3x^300

The gray image is a code over GF(4) with n=360, k=7 and d=258.
This code was found by Heurico 1.16 in 1.67 seconds.