how to determine what video card my Dell Inspiron 3847 has so I can update driver?

I have a Dell Inspiron 3847.  The monitor no longer shows color, it is black and white - I bought a new monitor and also tested the monitor from my other computer. all three monitors are black and white so it is my computer. I have tried diagnosing from Dell's diagnostic page. All the tests I ran said my computer is fine. One test took 10 minutes, it looks like it tested graphics - but not the COLOR. I put in my expired express tag, and it identified my computer and gave me a list of updates.  I installed Dell Digital Delivery application update, Dell Update Setup because those were dated 2016. I tried to update HD 4000 Series Graphics Driver but it gave me an error message. Said that driver was not verified for my computer and returned me to Dell's Diagnostic page. I tried that 3 times. I'd like to know how I can find out what my graphics card or video card is and how I can get an update for it. I assume that my monitors are all black and white due to something on this Dell computer. It has been black and white for about 2 weeks.