There is a command to check colors but in your case you can simply wait for an image to appear. The test image would be a screenshot of the enabled button.
To wait for an image to appear use:
store | 360000 | !timeout_wait
← tell visualAssert to wait up 6 minutes for the image to show. The default value is 60s (one minute).visualAssert | image_of_button_normal_color.png
← this automatically waits for the image to appear. It re-checks every second until!timeout_wait
limit.
Here you can again use visualAssert to visually check if the new page is loaded. This time with a test image specific/unique to this new page, of course.
PS: All visual commands with image input (XClick, XClickRelative, visualAssert, visualVerify) automatically wait for the image to appear until the !timeout_wait
time is reached. I used visualAssert here because it seems best suited for your case.
PPS: For more complicated image-triggered workflows see If {picture} then {do this}