I'm running an Acer, don't know what kind because sadly my mother made me throw away the computer box. Anyways I logged off for a minute and when I had logged off I saw a little blue box in the corner. So I clicked it and it gave me all of these options to (I suppose) enhance my computer. So I clicked a few to just try it out and look. So one of them was "enhance contrast" or something like that and when I had clicked on it my computer went all black, purple, blue, and green. It looked like this (actual screenshots from my computer)
First off, you've enabled High Contrast for your theme - to change that see http://www.vistax64.com/tutorials/87194-theme-settings.html?filter
Second, other options that you may have enabled will usually be found under Control Panel --> Appearance and Personalization --> Ease of Access Center
SanDisk Ultra SDSSDHII-960G-G25 960 GB SATA III SSD (System)
Crucial MX100 CT256MX100SSD1 256GB SATA III SSD (User Tree)
2 * Seagate Barracuda 7200.12 ST31000528AS 1TB 7200 RPM SATA II Mech. HD
Seagate ST1500DL001-9VT15L Barracuda 7200.12 1.5 TB S
PSU
Thermaltake Black Widow TX TR2 850W 80+ Bronze Semi-Mod ATX
Case
ThermalTake Level 10 GT (Black)
Cooling
Corsair H100 (CPU, dual 140 mm fans on radiator) + Air (2 *
Mouse
Logitech MX Master (shared)
Keyboard
Logitech G15 (gen 2)
Internet Speed
AT&T Lightspeed Gigabit duplex
Operating System
Sabayon Linux (current, weekly updates, 5.1.x kernel)
Manufacturer/Model
Lenovo ThinkPad E545
CPU
AMD A6-5350M APU
Motherboard
Lenovo
Memory
8 GB
Sound Card
Conextant 20671 SmartAudio HD
Monitor(s) Displays
Lenovo 15" Matte
Screen Resolution
1680 * 1050
Hard Drives
INTEL Cherryvill 520 Series SSDSC2CW180A 180 GB SSD
In addition to John's post, it looks like you may have changed the color scheme to one of the High Contrast ones (black?). Check with this tutorial below to see if you have. If so, just select Windows Aero again.
SanDisk Ultra SDSSDHII-960G-G25 960 GB SATA III SSD (System)
Crucial MX100 CT256MX100SSD1 256GB SATA III SSD (User Tree)
2 * Seagate Barracuda 7200.12 ST31000528AS 1TB 7200 RPM SATA II Mech. HD
Seagate ST1500DL001-9VT15L Barracuda 7200.12 1.5 TB S
PSU
Thermaltake Black Widow TX TR2 850W 80+ Bronze Semi-Mod ATX
Case
ThermalTake Level 10 GT (Black)
Cooling
Corsair H100 (CPU, dual 140 mm fans on radiator) + Air (2 *
Mouse
Logitech MX Master (shared)
Keyboard
Logitech G15 (gen 2)
Internet Speed
AT&T Lightspeed Gigabit duplex
Operating System
Sabayon Linux (current, weekly updates, 5.1.x kernel)
Manufacturer/Model
Lenovo ThinkPad E545
CPU
AMD A6-5350M APU
Motherboard
Lenovo
Memory
8 GB
Sound Card
Conextant 20671 SmartAudio HD
Monitor(s) Displays
Lenovo 15" Matte
Screen Resolution
1680 * 1050
Hard Drives
INTEL Cherryvill 520 Series SSDSC2CW180A 180 GB SSD