How can i get or create custom color filter on image

[vikas-shrma]

Hi,

I am trying to create custom color filters by changing the values of vec3
"const mediump vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);" // this is for Monochrome color Filter

can any one please suggest me how can i create this custom color code for vec3