VGA color change question

This module is a large green rectangle with two smaller rectangles inside called right product and left product. What I want to do is click on the small rectangles and have them change to another color. The clicking will be done with another module that calls a PS/2 mouse. I can just link the color change to a button on the DE2 board and then call in the mouse code later. Here is what I want to say: if there is no button push, stay red. If there is a button click turn blue. A push in the right direction would be appreciated. Thank you.

module vga(CLOCK_50, VGA_HS, VGA_VS, VGA_R, VGA_G, VGA_B, VGA_CLK, VGA_BLANK, VGA_SYNC, KEY);

// module vga input and output signals

// Cyclone II system clock is 50 MHz

input CLOCK_50;

// VGA signals

output[9:0] VGA_R, VGA_G, VGA_B;

output VGA_HS, VGA_VS, VGA_CLK, VGA_BLANK, VGA_SYNC;

input[3:0] KEY;

// Define signals necessary to instantiate the vga_controller module

wire clock_25; //A derived 25MHz clock

wire displaying;

wire[9:0] v_pos;

wire[9:0] h_pos;

wire v_blank, h_blank;

wire[7:0] v_early, h_early;

reg[3:0] r, g, b;

// Create one hardware instance of a vga controller

vga_controller vga_i(CLOCK_50, VGA_HS, VGA_VS, VGA_R, VGA_G, VGA_B, VGA_CLK, VGA_BLANK, VGA_SYNC,

clock_25, r, g, b, displaying, v_pos, h_pos, v_blank, h_blank, v_early, h_early);

/* This always block controls the colors of each individual pixel on the vga.

* v_pos is the vertical position pixel coordinate being drawn (a row)

* h_pos is the horizontal position pixel coordinate being drawn (a column)

* The always block is activated whenever the v_pos or h_pos signal is changed by the

* vga_controller.

*/

always @(v_pos, h_pos)

begin

{r, g, b} = 0;//set screen to black

if(h_pos >= 325 && h_pos <= 525 && v_pos >= 200 && v_pos <= 400)//bottom 2/3 of the venting machine

{r,g,b} = {4'b0000,4'b1111,4'b0000};

if( h_pos >= 325 && h_pos <=345 && v_pos >= 100 && v_pos <= 199)//upper 1/3 of the vending machine, left side

{r, g, b} = {4'b0000, 4'b1111, 4'b0000};

if( h_pos >= 505 && h_pos <=525 && v_pos >= 100 && v_pos <= 199)//uppper 1/3 of the vending machine, right side

{r, g, b} = {4'b0000, 4'b1111, 4'b0000};

if( h_pos >= 325 && h_pos <=525 && v_pos >= 85 && v_pos <= 99)//top of vending machine

{r, g, b} = {4'b0000, 4'b1111, 4'b0000};

if( h_pos >= 405 && h_pos <=445 && v_pos >= 100 && v_pos <= 199) //center line dividing the rt and lf products

{r, g, b} = {4'b0000, 4'b1111, 4'b0000};

if( h_pos >= 346 && h_pos <=404 && v_pos >= 100 && v_pos <= 199)//left product

{r, g, b} = {4'b1110, 4'b0000, 4'b0000};

if( h_pos >= 446 && h_pos <=504 && v_pos >= 100 && v_pos <= 199)//right product

{r, g, b} = {4'b1010, 4'b1010, 4'b0100};

end

endmodule