jit.gl.slab texture and color problem

hi, i have written my first java external which draws some triangles within the sketch object. you can choose color or texture from max. this works fine(enable and disable texture....). the texture is created in max and java only binds the texture name. this works fine.
now i wanted to build in some shaders in max with slab. this works also fine, send the shaders to texture and bind them with java. but if i select color from max (disable texture in java), the color of my triangles are now a pixel value of my texture and not the color i sent by max to java. is there any special command? also if i dispose the slab nothing happened, the color i see is one pixel value of the texture.
thanks