How to change the font and color on multiple keyframes at once | Adobe After Effects Hey there I ran into a small problem creating a video, and I haven't used any video editing software before, so I am lost right now and I have no idea on how to solve my problem which problem goes like this... 

I have been creating a “typing effect” by adding a new keyframe for each letter to appear with two frames distance between keyframes, each sentence was put into a new layer (about 40 keyframes per layer, 4 layers). 

Each letter is written in Times New Roman font, 36 px size, color white. 
I never knew that the font details are written into each keyframe, and believed that I can adjust the font style color and size after I finish creating the effect (now praying for what I believed to be true). 

After I finished with the effect and tried to  change the font by selecting the entire text and choosing the desired font, a new keyframe was created which did changed the text font when the Time Indicator has reached its position on the timeline, but that is not what I wanted.

Here is what happens right now: the video starts, and each letter shows up in the font that was originally written into (Times New Roman) when the time indicator has reached its position, and after the entire sentence has already appeared and the last keyframe is reached, the entire sentence changes from Times New Roman to the font that I have selected when I created the keyframe.

And now I feel like I have to recreate the entire video by pre-selecting the desired font preferences so if you know any solution on how to change the font on already set keyframes please share it with me and you will save me a lot of time.

Any help is really appreciated!
not sure how you are creating the typewriter effect?? 

You can use or change the font or color to anything you want. 

Create the text then apply the typewriter effect. Adjust effect with the range selectors with the start/end keyframes.