leaf blocks COLOR error

leaf blocks using foliage colormap have 1.0 alpha value

input/output

parts of vertex shader(renderchunk.vertex)

varying vec4 color;

attribute vec4 COLOR;

color = COLOR;

parts of fragment shader(renderchunk.fragment)

varying vec4 color;

and I didn't touch color value

in renderchunk.fragment shader:

applied to birch, evergreen colormap(solid color)

if((color.a <= 0.1)){
diffuse.rgb*= 1.2;
diffuse.rgb*= color.g*2.8;
{{}}}

applied to foliage, grass colormap(gradient)

if((color.a == 1.0)){
diffuse.rgb*= 1.2;
diffuse.rgb*= color.g*2.8;
{{}}}