Help with ANSI Art effect

gl_FragColor = vec4(cha*col,1.);[/code:2u8pxu1u]
[img="https://cdn.pbrd.co/images/GU4f61p.png"]

But for each character shows a color+black, and i want to get  Light color+Dark color, something like this:
[code:2u8pxu1u]/gl_FragColor = vec4((cha+col)*col,1.);[/code:2u8pxu1u]
[img="https://cdn.pbrd.co/images/GU4g4yV.png"]

Now each character have two colors without black, but seems also changes the real black color of the entire image to light colors :S.

How can i fix it?

Here is the actual Shader code i'm using:

[code:2u8pxu1u]// Directlyfrom shadertoy ..By FMS_CAT
// Adapted by gigatron // have fun !

// AnsiArt version by Matriax 

precision highp float;

uniform float textureSizeWidth; //width of the texture
uniform float textureSizeHeight; //height of the texture
uniform float texelSizeX; //width of one texel 
uniform float texelSizeY; //height of one texel 
uniform mediump float seconds;
uniform mediump float pixelWidth;
uniform mediump float pixelHeight;
varying mediump vec2 vTex;
uniform sampler2D samplerFront;
vec2 iResolution = vec2( 1.0/pixelWidth, 1.0/pixelHeight);

uniform float zoom;

#define P(id,a,b,c,d,e,f,g,h) if( id == int(pos.y) ){ int pa = a+2*(b+2*(c+2*(d+2*(e+2*(f+2*(g+2*(h))))))); cha = floor(mod(float(pa)/pow(2.,float(pos.x)+0.0),2.0)); }

float gray(vec3 _i)
{
    return (_i.x+_i.y+_i.z)/3.;
}

void main()
{
    vec2 uv = -vec2(floor(gl_FragCoord.x/8./zoom)*8.*zoom,floor(gl_FragCoord.y/12./zoom)*12.*zoom)/iResolution;
    ivec2 pos = ivec2(mod(gl_FragCoord.x/zoom,8.),mod(gl_FragCoord.y/zoom,12.));
    vec4 tex = texture2D(samplerFront,vTex);
    float cha = 0.;
    
    {
        float g = gray(tex.xyz);
        if( g < .05 )
        {
          P(11,0,0,0,0,0,0,0,0);
          P(10,0,0,0,0,0,0,0,0);
            P(9,0,0,0,0,0,0,0,0);
            P(8,0,0,0,0,0,0,0,0);
            P(7,0,0,0,0,0,0,0,0);
            P(6,0,0,0,0,0,0,0,0);
            P(5,0,0,0,0,0,0,0,0);
            P(4,0,0,0,0,0,0,0,0);
            P(3,0,0,0,0,0,0,0,0);
            P(2,0,0,0,0,0,0,0,0);
            P(1,0,0,0,0,0,0,0,0);
            P(0,0,0,0,0,0,0,0,0);
        }
        else if( g < .25 ) // .
        {
            
          P(11,0,0,1,0,0,0,1,0);
          P(10,1,0,0,0,1,0,0,0);
            P(9,0,0,1,0,0,0,1,0);
            P(8,1,0,0,0,1,0,0,0);
            P(7,0,0,1,0,0,0,1,0);
            P(6,1,0,0,0,1,0,0,0);
            P(5,0,0,1,0,0,0,1,0);
            P(4,1,0,0,0,1,0,0,0);
            P(3,0,0,1,0,0,0,1,0);
            P(2,1,0,0,0,1,0,0,0);
            P(1,0,0,1,0,0,0,1,0);
            P(0,1,0,0,0,1,0,0,0);
            
            
        }
        else if( g < .5 ) // ,
        {
        	/*
          P(11,1,0,1,0,1,0,1,0);
          P(10,0,1,0,1,0,1,0,1);
            P(9,1,0,1,0,1,0,1,0);
            P(8,0,1,0,1,0,1,0,1);
            P(7,1,0,1,0,1,0,1,0);
            P(6,0,1,0,1,0,1,0,1);
            P(5,1,0,1,0,1,0,1,0);
            P(4,0,1,0,1,0,1,0,1);
            P(3,1,0,1,0,1,0,1,0);
            P(2,0,1,0,1,0,1,0,1);
            P(1,1,0,1,0,1,0,1,0);
            P(0,0,1,0,1,0,1,0,1);
            */
          P(11,0,1,0,1,0,1,0,1);
          P(10,1,0,1,0,1,0,1,0);
            P(9,0,1,0,1,0,1,0,1);
            P(8,1,0,1,0,1,0,1,0);
            P(7,0,1,0,1,0,1,0,1);
            P(6,1,0,1,0,1,0,1,0);
            P(5,0,1,0,1,0,1,0,1);
            P(4,1,0,1,0,1,0,1,0);
            P(3,0,1,0,1,0,1,0,1);
            P(2,1,0,1,0,1,0,1,0);
            P(1,0,1,0,1,0,1,0,1);
            P(0,1,0,1,0,1,0,1,0);
            
            
            
        }
        else if( g < .75 ) // -
        {
          P(11,1,1,0,1,1,1,0,1);
          P(10,0,1,1,1,0,1,1,1);
            P(9,1,1,0,1,1,1,0,1);
            P(8,0,1,1,1,0,1,1,1);
            P(7,1,1,0,1,1,1,0,1);
            P(6,0,1,1,1,0,1,1,1);
            P(5,1,1,0,1,1,1,0,1);
            P(4,0,1,1,1,0,1,1,1);
            P(3,1,1,0,1,1,1,0,1);
            P(2,0,1,1,1,0,1,1,1);
            P(1,1,1,0,1,1,1,0,1);
            P(0,0,1,1,1,0,1,1,1);
        }
 
         else // 100
        {
          P(11,1,1,1,1,1,1,1,1);
          P(10,1,1,1,1,1,1,1,1);
            P(9,1,1,1,1,1,1,1,1);
            P(8,1,1,1,1,1,1,1,1);
            P(7,1,1,1,1,1,1,1,1);
            P(6,1,1,1,1,1,1,1,1);
            P(5,1,1,1,1,1,1,1,1);
            P(4,1,1,1,1,1,1,1,1);
            P(3,1,1,1,1,1,1,1,1);
            P(2,1,1,1,1,1,1,1,1);
            P(1,1,1,1,1,1,1,1,1);
            P(0,1,1,1,1,1,1,1,1);
        }
	}
    
    //vec3 col = vec3(1.);
    vec3 col = tex.xyz/max(tex.x,max(tex.y,tex.z));
   // gl_FragColor = vec4(cha*col,1.);
    gl_FragColor = vec4((cha+col)*col,1.);

}[/code:2u8pxu1u]