Bought both RCT 1 and 2, they both load up fine its just everything is purply/pinkish and quite funky like im on a acid trip.

Ive tried all compatability modes, tried patching tried running as admin, i have windows 7 64 bit - and yet in the requirements windows 7 is listed.

Kind of disappointed wanted to play the game i enjoyed as a child and Gog has never before let me down.

I am having the same problem and i have tried everything i can think of. Did you solve this?

That's because of the lastest AMD drivers.
You have to run the game in wondowed mode now:
http://www.gog.com/forum/rollercoaster_tycoon_series/hack_run_rct2_in_windowed_mode/page1

Same problem with RTC1, AMD card, 5850. Tried disabling Aero, even Explorer.exe (that helped in Atomic Bomberman), still nothing.
Anyone know a fix? I tried the RTC2 hack, no cigar.

Yep, same problem here. Extremely annoying.

I've tried the ddraw hack which seems to be made for RCT2 and has almost no mention of getting it working for RCT1. It fixes the colours, but causes another problem where the mouse is locked into the top left 640x480 section of the screen, and it's the windows pointer, not the game pointyer. If you start clicking around, the game just crashes.

As it stands, the game is unplayable.

I finally found a ddraw replacement that seems to work ok with RCT1.

https://ddhack.googlecode.com/files/ddhack10.zip

It converts the game to play in windowed mode, and even lets you resize the window to see more of the park! I'm surprised the game functions properly with the increased display size.

No apparent option to scale the graphics though, which means if you're running in a high res like 1920x1200, the icons are quite small. Workaround is to reduce desktop resolution.

Thanks, that makes it playable for me. I'll just run the monitor on a lower rez.

Hm, funny, I had the same issue, and the only thing I did was to change the compatibility mode of the executable to XP SP3, and it works.

I was expecting having to do the same things as described here, but apparently, I don't need.
Give it a try before trying the hack, it allows for fullscreen in my case.

I did, it didn't work.. From what I understand, there's an issue with a recent Radeon driver that caused the color corruption.

I'm having the same issue. I've tried everything, I went through all the compatibility modes, colour depths, resolutions etc... I eventually just switched over to my Ubuntu laptop double clicked the installer. Installed the game. Double clicked the icon and it went in no issues. Full resolution with no weird funky colours. Crazy to think a windows game runs better on a non windows operating system (Ubuntu) than on Windows itself.

Strangely, the game now plays in fullscreen with proper colour for me. I updated the AMD video drivers a few days ago, but running the game after the update still showed wrong colours, so I'm not sure what's changed between then and now.

Was on a nostalgia trip today,looked for Rayman and RCT
I noticed both of them are available here and wondered how it's possible they have them if they are unplayable on Windows 7
Checked Rayman,I noticed it comes with DosBox,so I thought that's cool and this site includes patches and fixes (though the Designer levels don't work but who cares)

So then I decided to buy RCT,because I saw it's compatible with Windows 7...and boom,color bug
I think I will ask for a refund..sure it's just 3$ but the only reason I bought it was because I thought it's patched (unlike the pirated version that I downloaded 1552 times and same color bug)

Nanis, did you try putting the game into windowed mode? That fixed the colour bug for me. I do prefer fullscreen in a lower resolution though. My old eyes have trouble with the really small details at 1920x1200...

Yes it works as windowed mode
But it's not really a solution,more like a workaround..sadly

I've a Windows Vista x64 version and the game works with the correct colors. Probably is a exclusive Win7 problem because I'm both operational systems in my laptop and in Win7 I'd the same problem related here.