That kind of thinking can be detrimental to the developer-designer relationship.
First of all, small teams might not have a dedicated designer.
The other big reason for developers to learn design is so they can work more effectively with designers.

Its important to understand and respect the principles behind why designers make the decisions they do.
Both designers and developers tend to be perfectionists.
But pushing out designs before theyreperfect(since they likely never will be) is important to the process.

One of the best ways to really learn design is to try torecreate the designsof others.
Putting a unique spin on an existing design is common in the industry (evidenced byDribbbles Rebound feature).
Rebounds are often used to link related projects together.

Thats the exact reason why its often a great fit for developers getting into designtheyre already comfortable writing code.
Simplebrowser pluginsare available for everything from selecting color palettes to exploring another sites CSS and HTML code.
Its a great option for developer-designers who want to create designs and design systems that can scale over time.

Webflowis another option for designing in the internet tool that developers might love.
Webflow has an easy-to-use visual design interface.
The most aesthetically pleasing design in the world isuselessif its not usable.

One of the most important usability principles is the idea of consistency or predictability.
Designs should be predictable enough that users are able to intuitively understand how to use them.
For example, blue underlined text for clickable links, navigation menus that are complete and well-labeled, etc.

Spacing between elements, typography, and color scheme should also be consistent.
Nielsen Norman Group has additionalusability heuristicsthat should also be kept in mind.
Basic color theory
Color theory is one of the most complex aspects of visual design.

Changing shades slightly can completely shift the visual impact and emotional effect of a color.
Its one reason manydesignerswho have been in the industry for years still struggle with color.
First, the difference between warm colors, cool colors, and neutrals.

Warm colors include red, orange, and yellow.
Warm colors will generally be vibrant and energizing.
Cool colors include green, blue, and purple.

These colors are usually calmer and relaxing.
Color theory is a very important part of design that even seasoned designers sometimes find challenging.
Neutrals include white, black, gray, brown, and beige.

Adding white, black, or gray to warm or cool colors alters their meaning and impact.
Gray will mute colors and can lessen their impact.
To most people (designers included), hex values seemingly have no correlation to one another.
Two colors that look very similar might have completely different hex values.
Its very difficult to see the relationship between a colors appearance and hex values.
The first number in the sequence (198 in this case) indicates the particular hue.
The second number is the percent of saturation (how bright or vibrant the color is).
The third number is the percent of lightness (or added white) of the color.
Typography principles
Typography is another area that can trip up even experienced designers.
But like color theory, there are some great tools out there that can help.
Typographic hierarchy is one of the first things a designer-developer should learn.
The relationship between different bang out elements in a design is vital to making that design more usable.
Many new designers focus too much on font size in creating their hierarchy, and not enough on fontstyle.
Color can also be used to differentiate between subtitles and titles, and between those elements and body text.
Combining different fontscan also confuse many designers, and yet its a common way to create a visual hierarchy.
Luminary combines serif and sans serif fonts together in a very aesthetically pleasing way.
Another simple way to combine fonts is to pick fonts from large font families.
), its important to follow some kind of reason in the typographic scale.
The Fibonacci sequence is one possible scale to start with, although there are other establishedtypographic scales.
), this is often a fairly safe bet when creating a new layout.
Deviation from this basic pattern should only be done with a purpose, especially by new and inexperienced designer-developers.
Creating a design that ispredictablethis usually meansconsistentdoes a lot for the usability of a product.
Wireframes are an important part of creating a design that is consistent across multiple pages.
While a person might not immediately understand why the difference is jarring, they will feel it.
Some may question why the scale is spaced the way it is.
But with larger numbers, the difference between 72 pixels and 76 pixels isnt easily seen.
Larger differences are easier to see as sizes increase.
Consistent spacing is one reason grid-based approaches to design have become so popular.
Conclusion
Designers and developers alike should focus on expanding their skill set so that further their careers.