Transparent item in gui

[Wind_Blade]

So i ty to drawn a transparent item in a gui, So i start with the basic itemRender.drawnItemAndEffectIntoGui(); and i put a GlStateManager.color(1F, 1F, 1F, 0.5F) But it's not worked, so I looked at the code inside and noticed that the OpenGl does not affect the drawing of the items.
I decided to copy paste the code and change myself the transparency. However just by copying the code, without modifying anything, I have a pretty bizzare bug. I can not find the cause.

Yes it's the drawing items...

 

public void drawn(){
                GlStateManager.pushMatrix();
                GlStateManager.translate((float)xx, (float)yy, 100.0F + this.zLevel);
                GlStateManager.translate(8.0F, 8.0F, 0.0F);
                GlStateManager.scale(1.0F, -1.0F, 1.0F);
                GlStateManager.scale(16.0F, 16.0F, 16.0F);
                GlStateManager.translate(-0.5F, -0.5F, -0.5F);
                GlStateManager.color(1, 1, 1, 0.2f);
                IBakedModel model = itemRender.getItemModelWithOverrides(stack, mc.theWorld, mc.thePlayer);
                int color =  -1;
                Tessellator tessellator = Tessellator.getInstance();
                VertexBuffer vertexbuffer = tessellator.getBuffer();
                vertexbuffer.begin(7, DefaultVertexFormats.ITEM);

                for (EnumFacing enumfacing : EnumFacing.values())
                {
                    this.renderQuads(vertexbuffer, model.getQuads((IBlockState)null, enumfacing, 0L), color, stack);
                }

                this.renderQuads(vertexbuffer, model.getQuads((IBlockState)null, (EnumFacing)null, 0L), color, stack);
                tessellator.draw();
                this.itemRender.renderItemOverlayIntoGUI(fontRendererObj, stack, xx, yy, Integer.toString(stack.stackSize));
	        	GlStateManager.enableAlpha();
	        	GlStateManager.popMatrix();
}

	    private void renderQuads(VertexBuffer renderer, List<BakedQuad> quads, int color, @Nullable ItemStack stack)
	    {
	        boolean flag = color == -1 && stack != null;

	        for(int i = 0; i < quads.size(); i++){
	        	
	            BakedQuad bakedquad = (BakedQuad)quads.get(i);
	            int k = color;

	            if (flag && bakedquad.hasTintIndex())
	            {
	                k = mc.getItemColors().getColorFromItemstack(stack, bakedquad.getTintIndex());

	                if (EntityRenderer.anaglyphEnable)
	                {
	                    k = TextureUtil.anaglyphColor(k);
	                }

	                k = k | -16777216;
	            }

	            net.minecraftforge.client.model.pipeline.LightUtil.renderQuadColor(renderer, bakedquad, k);
	        }
	    }

 

So if you understand why it's do that or have a better way to make transparent item in a gui could you help me please